Impmon, Misguided Soul

Deathtouch, First Strike
{t}, Pay x life: Draw x cards, where x is the number of life paid through this effect.
When Impmon, Misguided Soul attacks, you may discard any number of cards. If you do, Impmon, Misguided Soul gains +X/-X until end of turn, where X is the number of cards discarded by this effect.