So i was fooling around in training, it would appear that yoshi has a full life (or at least close to it) wall combo using only 1/2 - 1 bar. It looks like this.
6K. W! (if opponent has back to you) 1B+K. 6[A]. 6B BE. 7K. W! 1K. 2B+K. A+K - 235 ish
6K. W! (if opponent is facing you) 1B+K. 66A BE. iMCF. 7K. W! 1K. 2B+K. A+K - 235 ish
After spending some time doing this if figured out 2 things.
1. Opponent must not have his/her knees touch the ground after the second W! before you 1K them.
2. After second W! opponent must start falling towards you (if you're not right in front of them, the 1K will launch too far an they can roll out of it)
If done properly opponent shouldn't be able to roll out of it
I don't know if it's character specific yet as I only tested it on pyrrha.
Also my bad if this was already stated earlier in the thread. I didn't want to read through the 50+ pages just to look XD