Deal damage to Screaming Nemesis.
Screaming Nemesis and Blazing Sunsteel trigger.
Resolve the Screaming Nemesis trigger, dealing damage to any target.
Resolve the Blazing Sunsteel trigger, dealing damage to Screaming Nemesis.
Repeat from step 2.

Infinite damage

Opponents can't gain life for the rest of the game

Blazing Sunsteel

Screaming Nemesis

Declare any creature as an attacker. Dawnsire triggers, dealing 100 damage to  Screaming Nemesis.
Screaming Nemesis triggers, dealing 100 damage to any other target

Near-infinite damage to one opponent

Dawnsire, Sunstar Dreadnought

Deal damage to Screaming Nemesis.
Screaming Nemesis triggers, dealing damage to any target
Guilty Conscience triggers, dealing damage to Screaming Nemesis.
Repeat from step 2.

Guilty Conscience

Deal damage to Screaming Nemesis.
Screaming Nemesis and Fiendlash trigger.
Resolve the Screaming Nemesis trigger, dealing damage to an applicable target.
Resolve the Fiendlash trigger, targeting you, but dealing damage to Screaming Nemesis instead due to Pariah.
Repeat from step 2.

Fiendlash

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 Screaming Nemesis.
Screaming Nemesis triggers, dealing that much damage to the opponent.

Fire Covenant

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

Repercussion

Cast Volcano Hellion by paying {2}{R}{R}.
When Volcano Hellion enters, it triggers, dealing an arbitarily large amount of damage to you and a creature. The damage that would be dealt to you is dealt to Screaming Nemesis instead due to Pariah.
Screaming Nemesis triggers, dealing an arbitrarily large amount of damage to an applicable target.

Infinite damage to one opponent

Volcano Hellion

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

Wheel of Misfortune

Pariah's Shield

Give Red Hulk and Screaming Nemesis indestructible using Heroic Intervention.
Deal damage to Red Hulk.
Red Hulk triggers, putting a +1/+1 counter on it and dealing damage to Screaming Nemesis.
Screaming Nemesis triggers, dealing damage to Red Hulk.
Repeat from step 3.

Infinite +1/+1 counters on a creature

Red Hulk

Heroic Intervention

Give Screaming Nemesis indestructible, if needed.
Cast Chain of Plasma by paying {1}{R}, dealing 3 damage to Screaming Nemesis and causing you to discard a card and copy Chain of Plasma targeting Screaming Nemesis
Taii Wakeen and Screaming Nemesis trigger.
Resolve the Taii Wakeen trigger, causing you to draw a card.
Resolve the Screaming Nemesis trigger, dealing 3 damage to any target.
Resolve the Chain of Plasma copy, dealing 3 damage to Screaming Nemesis and causing you to discard a card and copy Chain of Plasma targeting Screaming Nemesis.
Repeat from step 3.

Near-infinite damage

Infinite self-discard triggers

Infinite draw triggers

Near-infinite magecraft triggers

Infinite rummaging

Taii Wakeen, Perfect Shot

Chain of Plasma

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 Screaming Nemesis.
Screaming Nemesis triggers, dealing that much damage to an applicable target.
Resolve the Earthcraft trigger, untapping the earthbent land.
Repeat from step 3.

Combos with "Screaming Nemesis"