Genestealer Patriarch's first ability triggers, putting an infection counter on a creature an opponent controls.
Activate
Leech Bonder by paying ({U} magic symbol) and untapping it, moving the infection counter from the opponent's creature onto another creature you control.
Activate
Ashnod's Altar by sacrificing the creature with an infection counter on it, adding ({C} magic symbol) ({C} magic symbol) .
The creature dies, triggering
Resourceful Defense and
Genestealer Patriarch's second ability.
Resolve the
Resourceful Defense trigger, putting an infection counter onto another creature you control.
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.