Annulist

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters)

At the beginning of your upkeep, discard a card; deal 1 damage to all other creatures.

When this creature deals damage to another creature, its owner discards a card from their hand. If they cannot discard from their hand, that creature becomes a copy of this creature and is under your control.