Cast Apex Altisaur by paying {7}{G}{G}.
When Apex Altisaur enters, its first ability triggers.
Holding priority, cast Akroma's Will by paying its mana cost, giving creatures you control indestructible until end of turn.
Resolve the Apex Altisaur trigger, causing it to fight a creature you don't control.
If the opposing creature dealt damage to Apex Altisaur, Apex Altisaur's second ability and Wrathful Raptors trigger.
Resolve the Wrathful Raptors trigger, dealing damage to any opponent.
Resolve the Apex Altisaur trigger, causing it to fight a creature you don't control.
Repeat from step 4 until your opponents control no creatures. If they happen to control an indestructible creature with power above 0, this loop can be done infinitely.

Destroy all creatures opponents control

Near-infinite damage

Apex Altisaur

Wrathful Raptors

Akroma's Will

Cast Savage Order by paying {2}{G}{G} and sacrificing a creature with power 4 or greater excluding Wrathful Raptors, searching your library for Apex Altisaur, putting it onto the battlefield and giving it indestructible until your next turn.
When Apex Altisaur enters, its first ability triggers, causing it to fight a creature you don't control.
If the opposing creature dealt damage to Apex Altisaur, Apex Altisaur's second ability and Wrathful Raptors trigger.
Resolve the Wrathful Raptors trigger, dealing damage to any opponent.
Resolve the Apex Altisaur trigger, causing it to fight a creature you don't control.
Repeat from step 3 until your opponents control no creatures. If they happen to control an indestructible creature with power above 0, this loop can be done infinitely.

Savage Order

Declare any creature as an attacker. Dawnsire triggers, dealing 100 damage to  Wrathful Raptors.
Wrathful Raptors triggers, dealing 100 damage to target opponent.

Near-infinite damage to one opponent

Near-infinite damage to any target

Dawnsire, Sunstar Dreadnought

Cause Wrathful Raptors to take damage by any method.
Wrathful Raptors triggers, dealing damage to an opponent.
Guilty Conscience triggers, dealing damage to Wrathful Raptors.
Repeat from step 2.

Infinite damage

Card that gives indestructible

Guilty Conscience

Deal damage to Wrathful Raptors.
Wrathful Raptors and Repercussion trigger.
Resolve the Wrathful Raptors trigger, dealing damage to an applicable target.
Resolve the Repercussion trigger, dealing damage to Wrathful Raptors instead of you due to Pariah.
Repeat from step 2.

Repercussion

Pariah

Cast Fire Covenant by {1}{B}{R} and paying an amount of life equal to an opponent's life total, dealing that much damage to Wrathful Raptors.
Wrathful Raptors triggers, dealing that much damage to the opponent.

Fire Covenant

Cast Wheel of Misfortune by paying {2}{R}, choosing an arbitrarily large number and having Wheel of Misfortune deal that much damage to Wrathful Raptors instead of you due to Pariah if you chose the largest number.
Wrathful Raptors triggers, dealing that much damage to an applicable target.

Wheel of Misfortune

Earthbend a basic land you control.
Cast Legolas's Quick Reflexes by paying {G}, targeting the earthbent land.
Activate Earthcraft by tapping the earthbent land, targeting the earthbent land.
The land triggers, causing it to deal damage equal to its power to Wrathful Raptors.
Wrathful Raptors triggers, dealing that much damage to an applicable target.
Resolve the Earthcraft trigger, untapping the earthbent land.
Repeat from step 3.

Combos with "Wrathful Raptors"