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 on BiT Skyloft is obtaining the gratitude crystal near the village pumpkin patch; in order to achieve this during BiT, an early game file must have the ability to collect crystals written onto it using Reverse BiTMagic.
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.
After doing the Cistern Clip above and getting the Small Key, 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.
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.
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.
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.
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 Unused Strategies), the one used in runs is 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.
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.
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 20 damage all at once and skip the second half of the first phase.
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 will finish Koloktos's second phase in one round.
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, so it would be considered a TAS-only trick.
Here are three other ways of getting on the Basement Statue during Early Boss Key; these are not currently used in runs as the Highflip Method is more consistent or faster than these.
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.
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.