Felix Five Boots and Assimilation Aegis

Janosik

If you have Felix Five Boots in play, and you steal a creature with Assimilation Aegis and attack with it, the copied card goes to Greg's hand.

This is the type of bug that Oktagon would try and pretend was 'working as intended', but the rules text on Felix Five Boots is very clear:

It states "when a creature you control", and not "when a creature you own"

And it states "create a copy in your hand", and not "create a copy in it's owner's hand"