Banewasp Affliction

Enchant creature
When enchanted creature dies, that creature's controller loses life equal to its toughness.

Grist, the Hunger Tide

As long as Grist isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.

Brood of Cockroaches

When this creature is put into your graveyard from the battlefield, at the beginning of the next end step, you lose 1 life and return this card to your hand.