Sensei's Divining Top + Urza, Lord Protector + Skyswimmer Koi

Sensei's Divining Top

Urza, Lord Protector

Skyswimmer Koi

How it works

1. Cast Sensei's Divining Top by paying 0 due to Urza.
2. When Sensei's Divining Top enters, Skyswimmer Koi triggers.
3. Holding priority, 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.
4. Resolve the Skyswimmer Koi trigger, causing you to draw Sensei's Divining Top from your library, and then discard a card other than Sensei's Divining Top.
5. Repeat

This elegant loop relies on Urza, Lord Protector to slash the casting cost of Sensei's Divining Top down to zero, turning it into a free artifact that you can cast over and over. With Skyswimmer Koi already on the battlefield, every time that free artifact enters, you trigger a chance to draw and discard. You simply hold priority in response to Skyswimmer Koi's trigger and tap Sensei's Divining Top to draw a card and place itself back on top of your library, ensuring the Koi's resolution effortlessly draws it right back into your hand for another iteration.