Wormfang Manta | Aminatou, the Fateshifter | Spark Double (and one other card)

Cards

All permanents on the battlefield (
Aminatou with two or more loyalty counters on it and
Spark Double as a copy of
Aminatou and with two or more loyalty counters on it).

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
Hushbringer.
Wormfang Manta's second ability triggers, causing you to take an extra turn after this one.
Activate
Spark Double's second loyalty ability by removing a loyalty counter from it, blinking
Aminatou.
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.
Repeat each turn.

This combo has been estimated to be Ruthless (Bracket 4+).