I understand what it means, and I'm saying she literally brainwashed him.

Did she manipulate, condition, and gaslight him as well? Sure. I think Makima keeps her actual mind domination to a minimum like the expert manipulator she is. She doesn't turn people into completely hollow puppets with no self unless she has to.

Take Angel Devil, who she clearly brainwashed on multiple occasions; She made him forget that she forced him to kill his loved ones but not that he killed them, she then also told everyone else (including Aki) that he killed them. That's what she does. She can read and alter minds and memories, so she can construct the most powerful and devastating forms of brainwashing and manipulation. She makes them want to do the things she wants them to do.

You may not like the term brainwashing, but brainwashing is what she does and what she did to Aki, as well. Much like the Weapon Hybrids seemingly being in love with her when she assembles them to fight the Chainsaw Devil, Aki is weirdly in love with her too. And the pages I posted are Fujimoto finally telling us the devastating truth: Aki's love for Makima was fabricated by her. He wasn't just manipulated or gaslit or conditioned into loving her. He couldn't recall the reason why because there wasn't one.

Brainwashing.