Genestealer Patriarch + Viscera Seer + Reyhan, Last of the Abzan + Rikku, Resourceful Guardian

Genestealer Patriarch

Viscera Seer

Reyhan, Last of the Abzan

Rikku, Resourceful Guardian

How it works

1. Declare Genestealer Patriarch as an attacker.
2. Genestealer Patriarch's first ability triggers, putting an infection counter on a creature an opponent controls.
3. Activate Rikku's ability by paying its cost, moving the infection counter from the opponent's creature onto a creature you control.
4. Activate Viscera Seer by sacrificing the creature with an infection counter on it.
5. When the creature dies, Reyhan and Genestealer Patriarch's second ability trigger.
6. Resolve the Reyhan trigger, putting an infection counter onto another creature you control.
7. Resolve the Genestealer Patriarch trigger, causing you to create a token copy of the sacrificed creature that is a Tyranid in addition to its other types.
8. Resolve the Viscera Seer ability.
9. Repeat from step 4.