Cast Sekki by paying {5}{G}{G}{G}.
When Sekki enters, Warstorm Surge triggers, targeting Sekki. Sekki prevents the 8 damage that would be dealt to it and instead removes eight +1/+1 counters from Sekki and creates eight 1/1 Spirit creature tokens.
Sekki dies as a state-based action due to having 0 toughness.
When the Spirits enter, Warstorm Surge triggers that many times, dealing a total of 8 damage divided among any number of targets.
Activate Sekki by sacrificing the eight Spirit tokens, returning Sekki from your graveyard to the battlefield.
Repeat from step 2.

Infinite damage

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Sekki, Seasons' Guide

Warstorm Surge

Activate Ashnod's Altar by sacrificing Sekki
When Sekki dies, One with the Kami triggers, creating at least eight 1/1 Spirit creature tokens.
Activate Sekki by sacrificing eight Spirits, returning it from your graveyard to the battlefield.
Repeat.

Infinite colorless mana

One with the Kami

Ashnod's Altar

Cast Sekki by paying {5}{G}{G}{G}.
Sekki enters the battlefield as a Bear due to Kudo.
Ayula triggers, causing Sekki to fight a creature you don't control.
Sekki removes a number of +1/+1 counters from it equal to the damage it would've been dealt and creates that many 1/1 Spirit creature tokens, which are Bears due to Kudo.
When the Spirit Bear(s) enter the battlefield, Ayula triggers that many times.
If Sekki is on the battlefield, resolve an Ayula trigger, causing Sekki to fight a creature you don't control, and then repeat from step 3.
If Sekki is not on the battlefield, activate Sekki by sacrificing eight Spirits, returning it from your graveyard to the battlefield as a Bear with eight +1/+1 counters on it due to Kudo.
If Sekki entered the battlefield, Ayula triggers, causing Sekki to fight a creature you don't control.
Repeat from step 3.

Destroy all creatures opponents control whenever a creature enters the battlefield under your control

Ayula, Queen Among Bears

Kudo, King Among Bears

Activate Goblin Bombardment by sacrificing another creature, targeting Sekki. Sekki will prevent the 1 damage that would be dealt to it and instead removes a +1/+1 counter from it and creates a 1/1 Soldier and a 1/1 Spirit creature token.
Repeat step 1, sacrificing the Soldier, until Sekki dies as a state-based action due to having 0 toughness.
Activate Sekki by sacrificing eight Spirits, returning it from your graveyard to the battlefield.
Repeat.

Combos with "Sekki, Seasons' Guide"