We could go the Guilty Gear route and have a 3 pronged system involving a RISC gauge that scales damage up or down based on a PER MOVE BASIS (every move has its own on hit and block risc values modifiers), have a guts rating (more damage scaling, up and down) and a defensive stat itself, which again, is more damage scaling, up and down. Some of this is per move, some is per combo, some is per health % at the start of a combo, some is effected by blocking before being opened up.. it is it's special corner of "wtf will I do if I land this" hell.
NRS's system isn't particularly elegant and small differences can make a huge impact (we've all seen tournament runs live and die on a pixel) but I just don't know a good way to list universal damage/% values unless we make some kind of calculator for each character, so you can do combo on, say, Superman (who I use) and it does 400 damage.. plug that into a calculator and choose a character and it spits out the damage to that character and the % of that character's life bar... Assuming this all happen as a whole...
Ie, let's say we take two identical combos on Supes. Identical in damage that is. One is say, I dunno, 8 hits for 350 damage, one is 14 hits for 350 damage... Does the defense stat effect these differently? Or will the same two combos always net the same damage number, even if that actual number changes based on the character?
If it does, then optimal combos could differ depending on who you're fighting. Maybe not enough to matter, but like I said, tournament runs live and die by a pixel pretty often.