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 creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Sekki, Seasons' Guide

Warstorm Surge

Activate Blasting Station by tapping it and 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 Spirit creature token.
When the Spirit enters, Blasting Station triggers, untapping Blasting Station.
Repeat steps 1 and 2 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.
When Sekki enters, Blasting Station triggers, untapping Blasting Station.
Repeat.

Blasting Station

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

Lock

Ayula, Queen Among Bears

Kudo, King Among Bears

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

Activate Spawning Pit by sacrificing Sekki.
When Sekki dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect.
Resolve the Spawning Pit ability.
Repeat.

Combos with "Sekki, Seasons' Guide"