Cast a copy of Scrollboost by paying {1}{W}.
Kykar and Storm-Kiln Artist each trigger.
Resolve the Kykar trigger, creating a 1/1 Spirit creature token.
When the Spirit enters, Spiritcall Enthusiast triggers, causing it to become prepared.
Resolve the Storm-Kiln Artist trigger, creating a Treasure token.
When the Treasure enters, Spiritcall Enthusiast triggers, causing it to become prepared.
Resolve Scrollboost, giving up to two creatures each +2/+2 until end of turn.
Activate Kykar by sacrificing the Spirit, adding {R}.
Activate the Treasure by tapping and sacrificing it, adding {W}.
Repeat.

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Infinite creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite magecraft triggers

Infinite storm count

Infinitely large creatures you control until end of turn

Kykar, Wind's Fury

Storm-Kiln Artist

Spiritcall Enthusiast // Scrollboost

Cast any instant or sorcery by paying its cost.
Stormsplitter triggers, creating a token copy of itself.
When that token enters, Spiritcall Enthusiast triggers, becoming prepared.
Resolve the instant or sorcery from step 1.
Cast a copy of Scrollboost from exile by paying {1}{W} and unpreparing Spiritcall Enthusiast.
Both Stormsplitters trigger, creating two more token copies of Stormsplitter.
When a token enters, Spiritcall Enthusiast triggers, becoming prepared.
Resolve the copy of Scrollboost, giving one or two creatures +2/+2 until end of turn.
Activate Phyrexian Altar by sacrificing one Stormsplitter token, adding {W}.
Activate any mana source, adding an additional {1}.
Cast a copy of Scrollboost from exile by paying {1}{W} and unpreparing Spiritcall Enthusiast.
At least three Stormsplitters trigger, creating at least three more token copies of Stormsplitter.
When a token enters, Spiritcall Enthusiast triggers, becoming prepared.
Resolve the copy of Scrollboost, giving one or two creatures +2/+2 until end of turn.
Activate Phyrexian Altar by sacrificing two Stormsplitter tokens, adding {W}{W}.
Repeat from step 11 any number of times.
Once you have infinite Stormsplitter tokens, you may activate Phyrexian Altar any number of times, adding infinite mana.

Infinite colored mana

Infinite creature tokens with haste

Stormsplitter

Phyrexian Altar

Cast a copy of Scrollboost by paying {1}{W}.
Dovescape triggers, countering Scrollboost and causing you to create two 1/1 flying Bird creature tokens.
When the tokens enter, Spiritcall Enthusiast triggers, becoming prepared.
Activate Phyrexian Altar twice by sacrificing both Bird tokens, adding {W}{W}.
Repeat.

Dovescape

Activate Blistercoil Weird using the ability granted to it by Elemental Mastery by tapping it, creating a number of creature tokens.
When the token(s) enter, Spiritcall Enthusiast triggers, causing it to become prepared.
Activate Phyrexian Altar by sacrificing a creature token, adding {W}.
Cast a copy of Scrollboost by paying {W}, targeting any valid target(s).
Blistercoil Weird triggers, giving it +1/+1 until end of turn and untapping it.
Resolve Scrollboost, giving up to two creatures +2/+2 each until end of turn.
Repeat.

Infinite creature tokens that are infinitely large

Blistercoil Weird

Elemental Mastery

Combos with "Spiritcall Enthusiast // Scrollboost"