Wily Tactician

Whenever you cast a spell with {x}
in its mana cost, put X +1/+1 counters
on Wily Tactician, where X is half
the converted mana cost of that spell,
rounded down.
Whenever Wily Tactician attacks,
target creature gets +X/-X until end
of turn, where X is Wily Tactician's
power.