Falco Spara, Pactweaver + Sensei's Divining Top + Etherium Sculptor + Stark's Ingenuity

Falco Spara, Pactweaver

Sensei's Divining Top

Etherium Sculptor

Stark's Ingenuity

How it works

1. Activate Sensei's Divining Top's second ability by tapping it, causing you to draw a card and put Sensei's Divining Top on top of your library.
2. Stark's Ingenuity triggers, putting a +1/+1 counter on the creature it's attached to
3. Cast Sensei's Divining Top from the top of your library by paying 0 and removing a counter from a creature you control.
4. Repeat.

This clever loop relies on Falco Spara, Pactweaver to fundamentally rewrite how you cast your spells, letting you remove a counter from a creature you control instead of paying mana. Sensei's Divining Top naturally replaces itself by drawing a card and slipping back onto the top of your library, where Falco Spara is already letting you look at it and cast it at will. To fuel this indefinitely, Etherium Sculptor steps in to make the Top cost zero to cast, entirely eliminating mana requirements. Finally, Stark's Ingenuity ensures that every time that Top is drawn and re-cast, its triggered ability constantly replenishes the +1/+1 counters on your creature, giving Falco Spara a fresh resource to spend on the very next iteration.