All or nothing

Players can't gain life. Damage can't be prevented. All damage is dealt as though its source had wither. (A source with wither deals damage to creatures in the form of -1/-1 counters.)

Flying Wither (This deals damage to creatures in the form of -1/-1 counters.) Creatures your opponents control with counters on them can't attack or block.

Whenever one or more creatures attack, this enchantment deals damage to each of those creatures equal to the number of attacking creatures.