Wizard Mentor + Wormfang Manta + Torpor Orb

Wizard Mentor

Wormfang Manta

Torpor Orb

How it works

1. During your precombat main phase, cast Wormfang Manta by paying 5.
2. Wormfang Manta's first ability does not trigger due to Torpor Orb.
3. Activate Wizard Mentor by tapping it, returning it and Wormfang Manta from the battlefield to your hand.
4. When Wormfang Manta leaves the battlefield, its second ability triggers, causing you to take an extra turn after this one.
5. Cast Wizard Mentor by paying 2.
6. Repeat each turn.