Sage of Hours + The Ten Rings + Putrid Imp + Stark's Ingenuity

Sage of Hours

The Ten Rings

Putrid Imp

Stark's Ingenuity

How it works

1. If you have six or more cards in hand, activate Putrid Imp by discarding a card.
2. Repeat step 1 until you have five or fewer cards in hand.
3. At the beginning of your end step, The Ten Rings triggers, causing you to draw cards until you have ten cards in your hand.
4. Stark's Ingenuity triggers for each card drawn, putting that many +1/+1 counters on Sage of Hours.
5. Activate Sage of Hours by removing all +1/+1 counters from it, causing you to take at least one extra turn after this one.
6. Repeat each turn.

This clever loop turns the straightforward card-refilling engine of The Ten Rings into an infinite turn machine. By carefully discarding down to five or fewer cards using Putrid Imp's activation cost during your main phase, you ensure that The Ten Rings triggers at your end step to refill your hand back up to ten. Each of those drawn cards triggers Stark's Ingenuity to pile +1/+1 counters onto Sage of Hours, providing the exact fuel needed to activate the Sage's ability and take an extra turn.