Shuri, Wakandan Inventor + Mindslaver + Generous Plunderer

Shuri, Wakandan Inventor

Mindslaver

Generous Plunderer

How it works

1. At the beginning of your upkeep, Generous Plunderer triggers, creating an artifact token.
2. Activate Shuri by paying 1 and tapping it, causing the artifact token to become a copy of Mindslaver that isn't legendary.
3. Activate the artifact token by paying 4, tapping and sacrificing it, causing you to gain control of target opponent during their next turn.
4. Repeat during each of your turns.