Infinite combat damageInfinite combat phasesInfinite death triggersInfinite creature ETBInfinite creature LTBInfinite mana creatures you control can produceInfinite creature sacrifice triggersInfinite untap of creatures you control
How it works
During your combat phase, before attackers are declared, activate the creature with Splinter Twin attached by tapping it, creating a token copy of the creature with haste.
Deal combat damage to an opponent using the creature with Breath of Fury attached.
Breath of Fury triggers, causing you to sacrifice the creature with Breath of Fury attached, then attach Breath of Fury to a creature token you control, untap all creatures you control and to get an additional combat phase after this one.