Kulrath Knight

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.

Cinderbones

Wither (This deals damage to creatures in the form of -1/-1 counters.)
{1}{B}: Regenerate this creature.

Blowfly Infestation

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

Sickle Ripper

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Swamp

Power of Fire

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to any target."