Stoneplate reduces Camille's true damage but not Cho'Gath's.

Her true damage is converted from her normal damage, so, for whatever reason, it applies Stoneplate's reduction.

Basically pasta coding.

The whole Cho'Gath getting more damage from his Ult while Camile deals less true damage meme is quite old.

And still fucking bullshit (of riot not fixing stoneplate already).

Yes it does, it does reduce Cho's damage, except the damage he gets from the health outways the mitigation from using stoneplate.

true damage is immune to any and all reductions. damage reduction aswell as damage mitigations and resistances. hence why it is called TRUE damage.