Sheev, Pyrrhic Strategist

Creatures may attack their controllers.
Whenever a creature deals combat damage to a
player, that player may pay {1}.
If they do, the creature's controller draws a card.
{p/u}: Target creature gets -1/-0 until end of turn.
{p/r}: Target creature gets +1/+0 until end of turn.
Any player may activate Sheev's abilities.