Karthus, the Deathsinger

When Karthus, the Deathsinger enters the battlefield or dies, he deals 1 damage to each
other creature on the battlefield.
{5}, Exile Karthus, the Deathsinger from your graveyard or from the battlefield: You may
destroy up to one target creature, that was dealt
damage by Karthus this turn. Return Karthus to
its owner's hand, at the beginning of their next
upkeep.