Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
Whenever a creature you control attacks, if it enlisted a creature this combat, the creature that attacked gains
double strike (This creature deals both first-strike and regular combat damage.) until end of turn. If that creature's power is 4 or greater, draw a card.