Ok so I have 2 damage questions.
First of all, do counterhits add damage? It seems they do from the fact that my combos can do several hundred more damage when I start them with a counterhit j.C for characters like Kouma, then into their normal BnB. Also, when I'm playing against the computer Kohaku, twice now I've been counterhit by EX Molotovs, and they've done well over 3800, once hitting around 4100 damage. I'm fairly sure it shouldn't ever do over 4000 alone, but it did when I got counterhit right in the middle of it. Still, I'm not sure and I just wanted to check since even given I was right in the middle of the EX Molotov, I've never thought a single EX could hit over 4000 damage without being part of a combo.
Also, I don't think anyone's really observed this before, since it's so impractical, but when I'm in practice and working on a combo a part at a time, I noticed that as you do a combo over and over, it weakens. For example, I was working on Sion's Cutting Sync resets, while leaving out the 2A 2A at the beginning, and I noticed that I would do the first part of the loop for like 2500, then they fall down, get up, and I start the combo over, the second time it would drop to like 2100 with nothing else changed, then it would go to like 1600, and it kept dropping. Once I started the combo off with 2A 2A, it immediately went back to full damage. Actually, now that I think about it, it could be Reverse Beat penalty, but just wanted to make sure, since I didn't know Reverse Beat penalty could carry over between combos.