IS: Infinite Stratos

[KrayZ33]

exactly...

in an RPG game this would be a berserker class IS (in most cases)
or if you play league of legends, take Sions enrage ability as an example (each attack costs health but deal more damage)
or Lost Planet T-Eng weapons (probably the best comparison)

and there is no difference in life-death-battle and the sports battle
if your shield reaches zero points you have lost your defence and the next hit will finish you off, the sports-battle will just stop right before that happens

so its a double edged sword in both cases and equally dangerous to use.. but it can end everything with a single blow...(or 2... who knows how much attack power he will gain
but from what his Sister (that weapon was the key to victory) it sounds like she had problems fighting certain enemies, maybe because she couldn't hit them too often because they were too fast, and that attack helped her dealing enough damage.