Vantablast

The user shoots a blast of purple & black energy. Roll 3 20-sided dice. (Cannot be under 11. If the roll was, reroll. )If any of these are a critical (20) then roll another die(s) based on how many dice scored a 20. (You )Keep on rolling until you don't get a 20 (CRIT). But there's a catch- since Vantablast is so powerful, it will drain 50% (half) of the CURRENT health points of the user. (round to the nearest 10ths. This only applies for players' characters who have an odd amount of hitpoints.) If you rolled over 3 dice, then lose 5 hp per die.