Vigor + Hanabi Blast + Crystalline Crawler + Conspiracy Theorist + Doubling Season

Vigor

Hanabi Blast

Crystalline Crawler

Conspiracy Theorist

Doubling Season

How it works

1. Cast Hanabi Blast by paying 1, targeting Crystalline Crawler.
2. Resolve Hanabi Blast, putting four +1/+1 counters on Crystalline Crawler due to Vigor's first ability, and then returning Hanabi Blast to your hand and discarding a card at random.
3. Conspiracy Theorist's second ability triggers, allowing you to exile the discarded card from your graveyard if it was a nonland card and cast it from exile this turn.
4. Activate Crystalline Crawler's first ability three times by removing three +1/+1 counters from it, adding 1.
5. Cast Hanabi Blast either from your hand or from exile by paying 1.
6. Repeat from step 2.
7. Once you have infinite colored mana, you may instead target any other creature and/or player with Hanabi Blast.

This explosive loop centers on the brilliant synergy between Vigor and Doubling Season: when Hanabi Blast targets Crystalline Crawler, Vigor prevents the damage and instead places +1/+1 counters on it, which Doubling Season then doubles into a massive cache of counters. You can then tap into Crystalline Crawler's mana ability by removing those newly minted counters, generating the exact red and colorless mana needed to recast Hanabi Blast. Meanwhile, whenever Hanabi Blast forces you to discard a card at random, Conspiracy Theorist happily catches the discarded nonland card in exile, letting you cast it right back if you ever need to pivot or fuel additional loops.