Mill out your opponents and cast their spells, or maybe just thoracle/doomsday!
Try to mill out whichever opponent most likely has the most fun/coolest instants and sorceries for Wrexial to steal, and hit them with Wrexial. Also, there's a bunch of control/interaction to protect a doomsday thoracle combo for playing at powerful tables.
Doomsday. This card basically reads: BBB: Cheat at magic. The easiest way to play this is to choose some combo of the following, from the top of the 5 card pile down:
From here, use any of the many ways in the deck to draw a card (looters, etc.), and cast brainstorm. If you've got enough devotion to blue, play Thassa's oracle and win. Otherwise, choose the lab-man plan and try to draw out this turn. This is prone to user-error, and I've lost a few games to myself playing this, and that's always pretty hilarious.
If playing at a lower-powered table, just don't use the thoracle/doomsday combo to win out of nowhere. Focus on the mill/slapping-people-with-Wrexial plan.