Agrus Kos, Eternal Soldier + Soulbright Flamekin + Deflecting Swat + Felidar Guardian + Donnie & April, Adorkable Duo

Agrus Kos, Eternal Soldier

Soulbright Flamekin

Deflecting Swat

Felidar Guardian

Donnie & April, Adorkable Duo

How it works

1. Activate Soulbright Flamekin by paying 2, targeting Agrus Kos.
2. Agrus Kos triggers, causing you to pay 1R/W to copy Soulbright Flamekin's ability targeting each other creature you control.
3. Resolve all Soulbright Flamekin triggers, giving the targeted creatures trample until end of turn and adding eight .
4. Cast Felidar Guardian by paying 3.
5. When Felidar Guardian enters the battlefield, it triggers, targeting Agrus Kos.
6. Agrus Kos triggers, causing you to pay 1R/W to copy Felidar Guardian's trigger, targeting each other creature you control except Felidar Guardian.
7. Resolve the copies of Felidar Guardian's trigger targeting Soulbright Flamekin and Donnie & April, blinking Soulbright Flamekin and Donnie & April.
8. When Donnie & April enters the battlefield, it triggers, returning Deflecting Swat from your graveyard to your hand.
9. Holding priority, activate Soulbright Flamekin by paying 2, targeting Agrus Kos.
10. Agrus Kos triggers, causing you to pay 1R/W to copy Soulbright Flamekin's ability targeting each other creature you control.
11. Resolve all Soulbright Flamekin triggers, giving the targeted creatures trample until end of turn and adding eight .
12. Cast Deflecting Swat by paying 0, changing any of the remaining Felidar Guardian triggers not targeting Agrus Kos to target Agrus Kos instead.
13. Repeat from step 6.

This intricate loop transforms Agrus Kos, Eternal Soldier into a multiplier for targeted abilities, turning a single activation of Soulbright Flamekin into a massive influx of red mana. By weaving in Felidar Guardian to repeatedly blink your board, you continuously reset Soulbright Flamekin while triggering Donnie & April, Adorkable Duo to recur Deflecting Swat from your graveyard. Deflecting Swat then effortlessly redirects your remaining triggers back where they need to go, keeping the infinite cycle of etbs, mana, and spell casts fully operational.