I recently made a simplified version of a damage display system. This assumes you review your programming, or at least test it. And do not need and fault-checks. (If you do need those, I would suggest Flick's F_Damage system.)
trg = Target (As mob) to display the attack above.
n = The number to display.
col = The color you want the number to display as. (If left blank it will stay white.)