Genestealer Patriarch + Ashnod's Altar + Host of the Hereafter + Rikku, Resourceful Guardian

Prerequisites

• You control at least two additional creatures.
• Genestealer Patriarch does not have summoning sickness.
• An opponent controls a creature.
• Rikku does not have summoning sickness.

Steps

1. 1Declare Genestealer Patriarch as an attacker.
2. 2Genestealer Patriarch's first ability triggers, putting an infection counter on a creature an opponent controls.
3. 3Activate Rikku's ability by paying its cost, moving the infection counter from the opponent's creature onto a creature you control.
4. 4Activate Ashnod's Altar by sacrificing the creature with an infection counter on it, adding .
5. 5When the creature dies, Host of the Hereafter and Genestealer Patriarch's second ability trigger.
6. 6Resolve the Host of the Hereafter trigger, putting an infection counter onto another creature you control.
7. 7Resolve 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. 8Repeat from step 4.

Effects

• Infinite colorless mana
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers