So I decided to try this out on a few other characters still on 3DS battlefield starting position, and right away I got some odd results.
- Standing in front of DeDeDe and hitting him with Finishing Touch 65%
- Facing away from DeDeDe and hitting him with the late hitbox 76%
- Standing underneath the platform and hitting him with the buster sword 72%?!?
I'm going to try this with other characters, but DeDeDe died later then just the basic hitbox while Shiek died earlier. Also there were no sparks for the underneath hit but there were some for the others. Maybe some sort of WBKB shenanigans?
EDIT: I ran some tests and I'm fairly sure whatever this is has something to do with weight.
First off, characters close to normal (100) weight.
Mario Weight 98
- Front: 57%
- Back: 67%
- Sword: 56%
Cloud Weight 100
- Front: 61%
- Back: 71%
- Sword: 60%
Both of them have only a 1% difference from the regular hit to the sword hit from underneath. Next characters with the same weight but different fall speeds.
Roy Weight 95 Fall Speed 1.8
- Front: 64%
- Back: 74%
- Sword: 60%
Pac-Man Weight 95 Fall Speed 1.35
- Front: 56%
- Back: 65%
- Sword: 55%
Captain Falcon Weight 104 Fall Speed 1.837
- Front: 64%
- Back: 74%
- Sword: 62%
Yoshi Weight 104 Fall Speed 1.29
- Front: 54%
- Back: 64%
- Sword: 55%
Roy and Pac-Man, both slightly below 100 weight both die earlier from the sword hit. But Roy died 4% earlier while Pac-Man only had a difference of 1%. This is further complicated by the comparison of Yoshi and Falcon, as Yoshi lived longer then usual while Falcon did not. However, both Roy and Falcon died at the same percents for the front and back hit, but Falcon, who is heavier, lived longer from the sword hit. I'm going to test characters with the same fall speed but different weights next to see if I can get a reason for the Yoshi and Falcon disparity. However I think this next comparison proves that this has something to do with weight the most.
Fox Weight 79 Fall Speed 2.05
- Front: 69%
- Back: 80%
- Sword: 51%
Bowser Weight 128 Fall Speed 1.39
- Front: 55%
- Back: 65%
- Sword: 59%
King DeDeDe Weight 119 Fall Speed 1.95
- Front: 65%
- Back: 76%
- Sword: 72%
Even though Fox lived longer then Bowser in both the front and back hits by a large margin, Fox, one of the lightest characters in the game, died a whopping 18% earlier from the sword hit while Bowser, the heaviest character in the game, lived 4% longer. And it can't just be that fast fallers die earlier from the sword hit (which would be consistent with the other results) because DeDeDe, who is the second fastest faller lived longer from the sword hit. So it had to have something to do with the characters weight.
EDIT: Once again I get to testing and immediately get strange results.
Ganondorf Weight 112 Fall Speed 1.65
- Front: 58%
- Back 67%
- Sword 59%
Duck Hunt Weight 91 Fall Speed 1.65
- Front: 62%
- Back: 72%
- Sword: 60%
I have no idea why, but Duck Hunt dies later than Ganondorf from Finishing Touch even though Ganon is heavier and Ganon lives longer otherwise from vertical KOs than Duck Hunt does. I tested it from the ground too to make sure it wasn't some platform oddity and DHD died at 73% and Ganon died at 69%. By what witchcraft is Duck Hunt living longer than Ganon?