The whole purpose of a power play is to show off one's abilities. But there is no "power play" to be had if the MC is going to forget the whole thing. So it's all a completely wasted effort on Ava's part.
Regardless, my primary issue here is not the lack of precedence for Ava's abilities, it's her contradictory behavior.
Ava is a mastermind villain, efficient, calculating, she bides her time, she makes the MC do the dirty work and interferes only when she needs to.
Ava doesn't like complications. Using the powers is fine, but getting away with a situation without using powers is even better. This is because the overt and extensive use of powers can quickly cause complications, a lesson the MC struggles to learn properly.
Along that same vein, it's better to not have loose ends to tie up in the first place. The destruction of the agency base in and of itself is a massive loose end. Ava and the MC's mind control powers seem to be limited to in-person interaction, and probably cannot manipulate the agents 100+ miles away at another base.
The main thing Ava knows for certain about the agency is they specialize in dealing with super-humans, so she is going to avoid a direct confrontation with them in any capacity.
So from Ava's perspective, the best course of action would actually be to help the MC subdue Camilla into being his double agent than to take this unusually aggressive course of action that had a million unknowns. She doesn't know how many agents are present, she doesn't know the extent of their facility's security. Her "power play" came with far too many risks. It doesn't fit the character's established profile.
As you just said, we don't know much about Camilla. So where are you getting your assumptions from that Camilla isn't a rookie? Or simply couldn't be overconfident in her abilities to deal with the MC? She is clearly not immune to ignorance, so she can be outwitted - she knew the MC was the son of a powerful mentalist due to the agency profile, but still fell into a trap anyways. And undressing the MC and tying him to a chair could hardly be considered extensive countermeasures. What should have happened is agents on the other side of a 2-way mirror pressed a button that sealed and gassed the chamber the moment Ava tried to break free.
My scenario operates on the concept of procedure. I'm pretty sure assaulting a civilian during broad daylight in the middle of suburbia USA is not a part of any agency's procedure. It's more likely they'd attempt to kidnap him while he's asleep and vulnerable. But even that comes with its own array of other risks. Which is why I think Camilla would return to question the MC a second time. A person can be questioned more than once during an investigation as the circumstances change and new details come to light.
Observing a character's struggles and growth in a story is fine when there is actual struggling to observe.
The problem with this whole arc is it blatantly wrote itself into a corner - the MC blundered so hard by trusting Ava that it should have cost him his life. But the MC didn't get so much as a slap on the wrist for it, only because Ava conveniently wasn't strong enough to permanently take control, boo-hoo for her. It's plot armor at its thickest. This didn't set or raise any stakes, it only confirmed what we all already suspected of Ava. So it was incredibly off-putting to see how hard the dev is holding the MC's hand.
As absurd as this game's premise and its story are, it's not a parody game. It takes itself seriously just barely enough to warrant some cricitism wherever there is a spot of some particularly bad writing.
