You control a creature that can tap to produce at least ({G} magic symbol) .
Steps
Activate the mana-producing creature by tapping it, adding at least ({G} magic symbol) .
Activate
Questing Phelddagrif's first ability by paying ({G} magic symbol) , giving it +1/+1 until end of turn and causing target opponent to create a 11 Hippo creature token.
The Hippo enters the battlefield, triggering
Intruder Alarm and
Suture Priest's second ability.
Resolve the
Intruder Alarm trigger, untapping all creatures.
Resolve the
Suture Priest trigger, causing the Hippo token's controller to lose 1 life.
Repeat.
Results
Infinite creature tokens for opponents.
Infinite ETB for opponents.
Infinite lifeloss.
Infinitely large
Questing Phelddagrif until end of turn.
Infinite mana creatures you control can produce.
Infinite untap of creatures.
Infinite creature tokens for any number of opponents.