It’s kinda funny indeed to have achievements that are references to the pro players. The fact that they called it “doubt castle” instead of “daut castle” gives the idea that they do not want to include names of real persons in their achievements, which I think is a good idea. So, the suggestion from the title and the silver boi are good suggestions. Although the name “I never play Arena again” seems to be totally unrelated to the condition for 99% of the players.
Some other things I think of now:
“I converted one monk, I convert it back” (Convert a monk back that was originally yours)
“Where’s my team!” (Win a team game with at least one ally being defeated)
“Doink” (Maybe this is already an achievement? I would suggest: kill a (weak) villager in feudal age with your starting scout within 3 tiles from the enemy TC)
Had also the Idea Build 3 Archer Ranges on a neutral Island on islands, but that is difficult to relate for players not watching streams.
Also I think a issue is, which “celebrities” get an achievement and who not. Does a player only get an achivement because you got a good idea?
No Forrest or Forrest Nothing - Cut down all trees on a map (and have at least 100.000 Wood in the bank?).
Lame Everything - Steal both boars and 4 sheep from the enemy and consume them.
Maybe skip latter since it motivates toxic play.
Unrelated to player: Forward University/Forward Wonder - build a University/Wonder within 10 tiles of the enemies starting Town center without destroying it.