For me it was Kai Leng in Mass Effect 3. In the intro cinematic he looked like a cool assassin that was sent after Shepard, but when you meet him he’s just a loser dweeb with insane plot armor and the power of anime on his side.
Another character for me is Alduin in Skyrim. The entire storyline hyped him up as The World Eater, that he will bring the apocalypse, but the when you do finally face him… I stg I’ve fought Draugr more fearsome.
That was actually my Destiny-Realization moment after I finished the Osiris DLC when they introduced him. The levels and story just completely flatlined for me. A few friends still played the game and were very lore heavy, and convinced me to come back. Oh my god was the Lightfall Story one of the worst fucking things I’ve ever experienced. Not only were the Neptune characters the most cookie-cutter basic personalities ever, they were insanely cringey. And yes, Osiris was suddenly some cliche old-man being grumpy and speaking absolute nonsense. What the fuck happened to you, Bungie? MTX??