Corviknight. It never peaked as high as some of the other nominees, but its been a very strong and stable presence in the tier for its entirety, which is imo what is embodied by a 'titan of the metagame'. My alternative votes would have gone to Dracovish, Urshifu-S, or Kyurem, for how they pretty much defined the metagame during their presence in the tier (things like Magearna or G-Darm were even more outrageous but also ended up banned so quickly, they feel more like temporary tiering errors instead of real defining presences), but ultimately I value stability a lot so I'm voting for Corv.