Coordinated Convergence

Assist (You may pay {2} and tap an untapped
creature you control rather than pay this spell's
mana cost.)
At the beginning of your upkeep, if an opponent
cast a spell last turn, you may create a 1/1 green
Elf creature token.
Whenever a player casts a spell, if it's not their
turn, you may pay {2}. If you do, you and that
player each draw a card.