This makes me wonder. When they do get owned, do they think: a) But I'm so strong! Why did this stupid mister human beat me!? or b) Yu...I guess I wasn't strong after all...
^Obviously A. And very probably they will claim that you're weren't fighting fair. After their defeat they tend to mark as cheting ANY action from your sifr, even stepping on it accidentally.
thouggh coloris, if they do get stonger, you would need to be careful, otherwise it would eventualy get stonger than you, but it might hide said extra stength for a while until it is extremely stong, and then kill you.
^^^^^ Possibly, they don't even realize they've been defeated. If the human leaves them alive, they think they have won by their strenght and persistence.