Dreadhorde Invasion [Commander Masters]

At the beginning of your upkeep, you lose 1 life and amass 1. (Put a +1/+1 counter on an Army you control. If you don't control one, create a 0/0 black Zombie Army creature token first.)

Whenever a Zombie token you control with power 6 or greater attacks, it gains lifelink until end of turn.