Infinite +1/+1 counters on a creatureInfinite death triggersInfinite creature ETBInfinite creature LTBInfinite mana creatures you control can produceInfinite storm countInfinite untap of creatures
How it works
Activate all mana-producing creatures you control by tapping them, adding at least 3.
Cast Hangarback Walker by paying 0.
Hangarback Walker enters the battlefield and dies as a state-based action due to having zero toughness.
Intruder Alarm and Mortuary trigger.
Resolve the Intruder Alarm trigger, untapping all creatures.
Resolve the Mortuary trigger, putting Hangarback Walker on top of your library from your graveyard.
Activate Hidetsugu's second ability by paying 2 and tapping it, exiling Hangarback Walker from the top of your library and allowing you cast it this turn.