Wormfang Manta + Aminatou, the Fateshifter + Spark Double + Torpor Orb

Wormfang Manta

Aminatou, the Fateshifter

Spark Double

Torpor Orb

How it works

1. Activate Aminatou's second loyalty ability by removing a loyalty counter from it, blinking Wormfang Manta. Wormfang Manta's first ability won't trigger due to Torpor Orb.
2. Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
3. Activate Spark Double's second loyalty ability by removing a loyalty counter from it, blinking Aminatou.
4. Activate Aminatou's second loyalty ability by removing a loyalty counter from it, blinking Spark Double. Choose to have Spark Double enter as a copy of Aminatou that isn't legendary.
5. Repeat each turn.