(Not sure if we have the scryfall bot here or not so I'm just going to pretend like we do)
Well, there's [[Havoc Festival]] + [[Wound Reflection]], and if anyone survives to make it to your turn, you just start skipping your own turn. Same schtick with the "Pact of ____" cycle
idk if you're already aware, but Obeka plays well with Myriad, making a slower-than-competitive but still explosively powerful style of play.
And [[Identity Thief]] is a fun exploration in the rules surrounding her, since she cancels the part where exiled things come back but doesn't cancel the thief returning to normal, allowing you to just exile a creature every turn until stopped.
Finally, Obeka naturally likes having backup spells like [[Discontinuity]], [[Stifle]], or [[Glorious End]], right? Well, those spells make for some really special fun when you start paying attention for cancellable triggers on opponents' turns. They send their commander for a ride in the [[Golden Argosy]]? Well, if you cancel the "return them all to the battlefield trigger", then that commander is trapped in exile forever. Oops.