One Gets You Two

Whenever another creature dies, you may put a +1/+1 counter on this creature. Remove a +1/+1 counter from this creature: It deals 1 damage to any target.

Whenever a creature dies, put a +1/+1 counter on equipped creature. If equipped creature is a Vampire, put two +1/+1 counters on it instead. Equip

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.) Equip (: Attach to target creature you control. Equip only as a sorcery.)