Genestealer Patriarch + Altar of Dementia + Host of the Hereafter + Rikku, Resourceful Guardian

Genestealer Patriarch

Altar of Dementia

Host of the Hereafter

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 Altar of Dementia by sacrificing the creature with an infection counter on it.
5. When the creature dies, Host of the Hereafter and Genestealer Patriarch's second ability trigger.
6. Resolve the Host of the Hereafter 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 Altar of Dementia ability.
9. Repeat from step 4.