Sensei's Divining Top + Elsha of the Infinite + Cheering Fanatic

Sensei's Divining Top

Elsha of the Infinite

Cheering Fanatic

How it works

1. Declare Cheering Fanatic as an attacker. When it triggers, choose to name "Sensei's Divining Top".
2. Activate Sensei's Divining Top by tapping it, causing you to draw a card and put Sensei's Divining Top on top of your library.
3. Cast Sensei's Divining Top from the top of your library by paying 0.
4. Elsha's prowess ability triggers, giving it +1/+1 until end of turn
5. Repeat from step 2

This clever engine is powered by Elsha of the Infinite, whose static ability lets you cast noncreature spells directly from the top of your library as though they had flash. With Sensei's Divining Top resting on top of your library, you can repeatedly tap it to draw a card and place the Top back on your library, then cast it right back out. To make this self-referential loop free, Cheering Fanatic steps in: whenever it attacks, naming "Sensei's Divining Top" reduces its casting cost by {1}, turning the Top's mana value of {1} down to zero. As you cycle the Top infinitely, Elsha's prowess trigger will continuously pump her power and toughness, generating an arbitrarily large creature alongside a towering storm count.