I think you remembered wrong, even after this trial it isn’t his full extent until later on.
Spoiler for others that read the comment.
This is where he knows where his power comes from (Osborn or the shadow monarch), yes he does get a significant boost up but he fully gets his power when he “died”. It’s when he was facing off the ice monarch and the other. He got stabbed in the heart and then his dad jumped in and held them back for a bit. It’s been awhile since I read it but so the details might be a bit off but that’s where he fully had Osborn power.

50 or more chapters the series will end I guess