msem-instigator

Tyrant of the Depths has hexproof as long as it's untapped.
Whenever you cycle Tyrant of the Depths or it attacks, tap target nonland permanent you don't control and put a stun counter on it.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)