Reaching the basement early can be done on any version, but with very different tricks; NTSC-U v1.0 has a version-exclusive trick called Cistern Clip, while other versions can use a Reverse BiTWarp via Faron BiT.
Using Faron BiT, it is possible to Reverse BiTWarp into the Ancient Cistern. If this is done from a save at a specific position, then the Reverse BiTWarp will grant you the ability to obtain the Boss Key early. Here is a list of statues that allow such a feat:
To escape the basement with methods that load you directly into the basement, you can enter and exit the statue after it lowers, then use one of several methods to get on top of the statue. The easiest method to use is the Highflip Method; go to the corner between the statue's right foot and the wall, then perform either a Sidehop Highflip or a Bomb Highflip and you should end up on the statue's foot. You can then navigate over the wall to the rope leading to the upper level and climb.
In addition to this, it can sometimes be faster to load the basement by swimming to a specific spot, instead of swimming to the rope loading zone. Here is a video showing it off:
As soon as you enter Ancient Cistern, you can see a tiny seam in the floor between the main dungeon floor and the stairs leading out of the dungeon. By positioning Link in exactly the right place, Link will fall through the floor and land out of bounds. From there you can make your way around the outside of the cistern to the rope exiting the basement, and then climb the rope to the loading zone for the basement. Since the statue was never lowered, you can then obtain the Blessed Idol early, thereby skipping over half the dungeon.
To more easily clip through the floor, run up the left hand wall just below the stairs, hold Z, and try to walk directly forward along the seam. You will be able to tell where the seam is when Link does a little hop.
This trick does not work in other versions because the seam in the floor does not exist.
With the Clawshots, one can simply clawshot over to the vines and skip most of the dungeon. Indeed, this allows anyone to lower the statue normally and reach the basement.
There is however another way to the basement, that is about 10 to 15 seconds faster. With the clawshots it is possible to perform a Vine Clip, and then maneuver OoB to the rope that leads into the basement. It skips lowering the statue, going down the statue, and performing the Early Blessed Idol trick.
If you do not have the water dragon's scale, then you cannot do the spin move to go through the waterfall that pushes you away. You have to jump into the oob water far down below you, and then swim back up oob, in order to avoid the waterfall.
It is possible to reach the Whip early while skipping the Small Key. It can be done on any version, but with very different tricks; NTSC-U v1.0 has a version-exclusive trick called Cistern Clip, while other versions can use a Reverse BiTWarp via Faron BiT.
Using Faron BiT, it is possible to Reverse BiTWarp into the Ancient Cistern. If this is done from a save at a specific position, then the Reverse BiTWarp will grant you the ability to obtain the whip early. Some will spawn you directly inside the statue, meaning that you won't even need the water scale if you have clawshots or if you are on NTSC-U 1.0, and some will spawn you underwater OoB in the main room and you only need to swim to the whip. Here is a list of statues that allow such a feat:
As soon as you enter Ancient Cistern, you can see a tiny seam in the floor between the main dungeon floor and the stairs leading out of the dungeon. By positioning Link in exactly the right place, Link will fall through the floor and land out of bounds. From there you can make your way around the outside of the cistern to the rope exiting the basement. Don't jump to the rope however. The floor doesn't exist around the rope so try falling into the water without grabbing the rope. Once underwater you can simply swim to the whip chest room, which will load around you.
After getting the Small Key and having the statue lowered, when you return to the statue to get the whip, it is a level lower than the game expects. You want to drop one level but not two; if you drop two levels, you will have to fight the Stalmaster on the bottom floor. By angling correctly and backflipping, you can land on the level below without falling to the bottom floor, then unlock the door that is locked from the other side to get the Whip.
It is also possible to do a forward jump in such a way that you grab the ledge of the lower level, thereby avoiding taking fall damage for runs that do not have the Sailcloth. This is somewhat precise but sometimes worth it if you need to preserve your health.
In the first room on the right side of the dungeon, there is a cutscene that plays when you land on a lilypad from above. If you manage not to land on a lilypad, you can skip this cutscene. You can avoid the lilypads by sidehopping off the upper platform at the correct angle, or by jumping off the ledge at the right angle and then doing a jumpslash in midair.
Using a precise jump from the vines to the tall platform, it's possible to clip into the wall. You can then jump into out of bounds water and swim back in bounds into the underwater tunnel, skipping having to flip the lilypad
This only saves about 2 seconds and is extremely precise. However it is necessary in JP speedruns that need the small key but don't have the water dragon scale (due to Reverse BiTWarping into Ancient Cistern). A setup does therefore exist:
It is possible to get rid of the lock on the door blocking the access to the statue (or to the whip chest if the statue is lowered) using Reverse BiTMagic, and thus skip obtaining the Small Key. This RBM is generally slower than simply obtaining the small key regularly, but it can be useful when you don't have the water dragon's scale and you do not want to perform the difficult lilypad skip.
The corresponding flag is Fx02. On BiT Skyloft it is set when obtaining the gratitude crystal on the western ledge, near the West Windmill; in order to achieve this during BiT, RBM must be used to enable gratitude crystals on an early game file. Thus, while this RBM itself is quite fast, it unfortunately has a pretty long setup required.
Similar to Moldarach, Stalmaster functions on a one hit = one damage principle; in particular, spin attacks and Skyward Strikes don't deal more damage. Stalmaster has two phases, but the general strategy is the same each time.
Perform the following attacks:
Here, the first hit of the spin attack will land but the second hit will be blocked, so this deals 5 damage.
Here, the spin attack is completely blocked, but both slashes and all three stabs land, so this also deals 5 damage.
In all cases, the stabs are optional, but greatly speed up the fight. If you are inconsistent getting three stabs, you could try two or even one stab. But it will take more rounds to defeat Stalmaster.
Starting with a spin attack when he is stunned is not optimal; it takes one extra slash to do the same amount of damage. Doing normal slashes when he is blocking results in a slow recoil animation, so spin attacking into the guard is faster.
The counter attack from Stalmaster has the same glitch as Power Crouch Stabbing in Ocarina of Time. It initially does only 1/2 heart of damage, which is the minimum amount in Hero Mode. However, if the Stalmaster does a different attack, the counter attack will deal the same amount of damage as that attack (either 2 or 4 hearts).
If the strategy is done correctly, Stalmaster should never do a different attack, so getting hit by a counter-attack will only deal 1/2 heart of damage. Therefore it is safe to do this strat on 2 hearts.
Stalmaster takes 10 hits in its first phase, and can therefore be finished in two rounds:
This will trigger his second phase.
Stalmaster takes 18 hits in his second phase. When he has 4 hits left, his helmet flies off, and the time his counter-attack takes is randomized, complicating the fight. There are two strats for this phase, a fast strat and a more consistent strat.
While this is the fastest strat, it requires getting good RNG for a long charge time on the Stalmaster's final counter-attack. If he counter-attacks quickly, you will get hit before you get all the stabs in.
This strat stops a round when Stalmaster has 5 hits left, thereby making the final three stabs easier to get in before his last counter attack. This strat is only a few seconds slower, so is recommended for full runs.
The Early Blessed Idol trick for non NTSC v1.0 versions has two parts: getting underneath the statue, then a deathwarp in the right position to keep the Blessed Idol without having to raise the statue first. While there are several methods that can be used to get underneath the statue (see below), the one used in runs is always the Highflip method.
When you enter the basement, go to the corner located to your right. Turn around so that you face away from the corner, and align the screen so that you face slightly toward the wall to your right. Perform a Sidehop Highflip and you should end up on the statue's foot. After that you can drop underneath the statue and grab the Blessed Idol.
Alternatively, you can use a Bomb Highflip to get onto the statue's foot instead.
To escape from underneath the statue with the Blessed Idol, you can deathwarp. However, the game is programmed so that if you die in that area, you do not keep the Idol. This is in case you fail to escape as the statue descends when playing the game casually.
However, there is one spot that is outside this programmed area. Deathwarping in this spot will allow you to keep the Blessed Idol after respawning, and thus skip having to raise the statue before getting the Idol.
It is possible to open the boss door at the top of the central statue using Reverse BiTMagic, and thus skip obtaining the Blessed Idol.
The corresponding flag is Cx10. On BiT Skyloft it is set when obtaining the gratitude crystal near the village pumpkin patch; in order to achieve this during BiT, RBM must be used to enable gratitude crystals on an early game file. Thus, while this RBM itself is quite fast, it unfortunately has a pretty long setup required.
Using a Stale Entrance Warp, one of the applications of Bed Trick, it is possible to load yourself directly near the Boss Entrance, at the very top of the room, even if the boss door wasn't opened and the statue not raised. To do this, go into the Ancient Cistern Basement by going down the rope first. This is entrance 2 in room 4. Then, use the main statue to climb back up to the main room, which is room 0, and save at the entrance statue. Now performing bed trick will load entrance 2 of room 0, which is near the boss.
This is especially useful when the boss door is not openable, for exemple when the game already considers the dungeon as completed, for exemple after Early Lanayru Song of the Hero, and more specifically doing the Imprisoned 1 rematch early.
After performing Early Lanayru Song of the Hero, it is possible to enter the Koloktos fight in Boss Rush. Normally, the door flags during rematches are zone flags or temporary flags, which makes them impossible to use to our advantage. Koloktos however is an exception, as the flag for unlocking the door back into the dungeon is a scene flag. It is thus possible to set early with the Reverse BiTMagic technique.
The corresponding flag is Ax02. On BiT Skyloft it is set by obtaning the bottle in the Bazaar or by buying anything from the Item Seller. To do this trick, enter the Ancient Cistern normally and perform the RBM. Then leave and enter the Koloktos fight in Boss Rush. You can now leave and save at the Boss Door Statue in Ancient Cistern. You cannot fight Koloktos yet, as this would warp you back to Lanayru Gorge. The ending door is also impossible to unlock in this state. To circumvent this problem, perform a bed or death trick to teleport another file to the Ancient Cistern Boss Entrance. This file will not be in boss rush state, and can fight Koloktos normally. This skips the Boss Key.
First bait two attacks from Koloktos's left and right axe arms; use the Whip to yank those arms off. Now try to bait an attack from both of its middle arms; the best way to do this is to stay a medium distance away from Koloktos. If you're too close, it will do a double axe slice attack. If you're too far, it will throw those axes like boomerangs to try to hit you. What you do next will depend on whether or not you have the Bomb Bag. During phase 1, Koloktos has 80 health, and will try to repair himself when he hits 40 health or below.
Once you've baited the correct attack, hit Koloktos with the whip as it is attacking. This manipulates its AI to do the correct attack next (the attack where he throws his weapons at you). Wait for him to start that attack and quickspin him twice to deal 96 damage, more than his 80 health pull. This works because Koloktos cannot regenerate during that attack.
Once you've baited the correct attack, hit Koloktos with the whip as it is attacking. This manipulates its AI to do the correct attack next. When his arms land, yank them off with the Whip, then immediately run forward and place two bombs next to Koloktos's heart. Do a spin attack to explode both bombs and hit Koloktos, and you'll deal the requisite 80 damage all at once and skip the second half of the first phase.
If you have the Sacred Bow for the Koloktos fight, then one uncharged arrow shot (32 damage) then one charged arrow shot (48 damage) will end phase 1.
Once you've baited the correct attack, pull both of those arms off, then perform one slash and one spin attack. This will deal 32 damage, less than the 40 that would cause Koloktos to reset his first phase. Then back off and whip his core. This will make it so that his next cued up attack will be a throw attack. Wait for that attack to start then perform 2 spin attacks to deal another 48 damage. In the end you will have dealt 80 damage, enough to enter the 2nd phase.
Once you've baited the correct attack, pull both of those arms off, then perform three spin attacks. This will deal 36 damage, just under the 40 that would cause Koloktos to reset his first phase. Then back off while charging a Skyward Strike. Once Koloktos winds up to do his boomerang attack, quickly hit him with your charged Skyward Strike (16 damage), charge another and hit him again (16 damage), then perform one last spin attack (12 damage). You will have dealt 80 damage in total and this will finish the first phase before Koloktos can reset; done optimally, this is 15 seconds slower than the bomb strat.
Koloktos' second phase has 28 healths, and your sword power is nerfed to only deal 1 damage per hit. The huge swords are made to deal 4 damage. However on hero mode your skyward strike will still cause its 16 damage, which allows for beating this phase in a single cycle.
Koloktos has three attacks during its second phase; however, you'll only ever see the first one, the sword attack. You can dodge by backing far enough away, or if your timing is good you can use the invincibility frames from a backflip to avoid the damage. Use the Whip to pull one of Koloktos' arms off, pick up its sword, and take out its legs with a horizontal slash. Use the sword to break the grating around Koloktos's heart, then back up and drop the sword. Two Skyward Strikes (or two uncharged arrow shots) will finish Koloktos's second phase in one round.
After entering the basement, you'll see a small ledge on the ground in front of the door. By running over this ledge, it is possible to make Link auto-jump, ultimately allowing you to jump up onto the statue's toe. After you're up on the statue, make your way over the rock wall in front of you.
Exactly how this is done is not known, and it is considered luck-based, but it is the fastest method, which makes it useful for segmented runs.
Lure a bokoblin to the left corner of the statue while facing it. Start to run up against the wall next to the statue. The bokoblin will start to push you toward the statue, allowing you to perform a full sprint. The bokoblin will continue to push you, and you'll land on the statue as a result. Now make your way over the rock wall located to your left.
Lure a bokoblin to the left corner of the statue while facing it. Attack the bokoblin so that it lands on the statues toes. Now perform a finishing strike while targeting the bokoblin. If the finishing strike misses, you will land on the statue. Now make your way over the rock wall located to your left.
When you reach the rotating drum of vines, climb up the vines and land on the first platform. You can then jump towards the further lower platform and do a jumpslash to reach it, skipping the second half of the vine drum and saving a little time.
Immediately after that, you need to pull a lever to open a gate, then use the whip to swing across to a vine wall. If you jump off the ledge then press and hold Z, you'll briefly target the whip target, and moving forward while still holding Z will allow you to target the lever from the ground. This saves having to swing to the lever.
This room is currently skipped in all speedruns, and thus these timesavers are not used.
It's possible to sidehop from the ledge and catch one of the later vine sections, saving around a second of climbing.
This strat is fairly precise and thus somewhat risky; if you miss the grab you'll lose time. This section is currently skipped in every speedrun, and thus this strat is not used.
In the first room on the right side of the dungeon, there is a pool with tree roots at the bottom of it. It is possible to swim through the floor near the left side of those tree roots and end up in out of bounds water. Unfortunately this leads to a dead-end, since the water does not extend laterally beyond the dimensions of the pool.
It is possible to run around the wall while the floor still is rotating if you sprint and then jump off of it when you reach the other side of the wall.