Not every one-trick will refuse to swap, occasionally some will eventually switch to try and tip the odds even if they’re worse at their non-oneitis.
What I’ve gathered:
Mercy OTPs : Moira. The most terrifying Mercy one tricks are the ones who can only swap to Moira. It usually means “DPS GOD DAMN YOU FUCKING SUCK I’LL DO IT MYSELF WITH EVIL MERCY”. Sometimes Kiriko.
Genji OTPs: Reaper. Usually when their Winston is really good, and they normally do good when they do so. Other than that, Soldier if they still can’t take down their Pharmercy.
Hanzo OTPs: Widowmaker or Ashe. Usually when their Widow is too good or they’re struggling against Pharmercy. Also Reaper if the Winston is really good.
Reinhardt OTPs: DVa when their own DPS can’t play hitscan well. Otherwise Orisa because Rein is really mid outside of gold.
Doomfist OTPs: Yes, this is rare. But usually Roadhog for some reason.
What others? Genuinely cuirious.
Genji/doom 1 trick here im thinkng about learning ashe or echo (stull gonna 1 trick him) im kinda leaning to echo since shes good into monked as well not just beam heroes and pharamercy I think ill just try to master these 2 and see how far I can climb
As for doom I have to plan on swapping the chadest hero în the game (unless they add Bob as a tank)