Cast Boros Reckoner by paying its mana cost.
Give Boros Reckoner indestructible.
Deal damage to Boros Reckoner.
Boros Reckoner triggers, dealing double that much damage to itself due to Neriv.
Repeat step 4 an arbitrarily large number of times.
Resolve the final Boros Reckoner trigger, dealing an arbitrarily large amount of damage to any target.

Infinite damage to one opponent

Neriv, Heart of the Storm

Boros Reckoner

Cast Ajani's Presence by paying {2}{W}{W} total, giving two creatures an opponent controls indestructible until end of turn.
Cast Toralf by paying {2}{R}{R}.
Deal noncombat damage to one of the indestructible creatures.
Toralf triggers, dealing an amount of damage over the excess damage to the second indestructible creature due to Neriv.
Toralf triggers, dealing an amount of damage over the excess damage to the first indestructible creature due to Neriv.
Repeat from step 3 an arbitrarily large number of times.
Resolve a Toralf trigger, dealing infinite damage to any target.

Toralf, God of Fury // Toralf's Hammer

Ajani's Presence

Activate Deathless Angel twice by paying {W}{W}{W}{W}, giving two creatures an opponent controls indestructible until end of turn.
Cast Toralf by paying {2}{R}{R}.
Deal noncombat damage to one of the indestructible creatures.
Toralf triggers, dealing double the excess damage to the second indestructible creature due to Neriv.
Toralf triggers, dealing double the excess damage to the first indestructible creature due to Neriv.
Repeat from step 3 an arbitrarily large number of times.
Resolve a Toralf trigger, dealing infinite damage to any target.

Combos with "Neriv, Heart of the Storm"