Ace knows she’s dangerous but she doesn’t necessarily believe herself to be strong in the sense that most superheroes, or even just other metas, are. Like, she is aware that her powers are kind of ridiculous but in the face of what she can see as flaws and weaknesses those powers don’t really make up for them?
She can induce madness in anyone but for a significant period of time it was a completely involuntary power, therefore not a strength.
She can passively hear surface level thoughts, but there’s no off switch. It’s a constant white noise of everyone around her and it affects her very deeply as she has to do her best not to be influenced by the emotions of those around her.
She can actively read a person’s mind but that means she gets everything–their entire mind with no filter and again, it takes a large amount of either time or effort on her part to sort through those thoughts she takes in or else she could get lost in them.
She can warp reality but at the cost of her own health and she never knows when it’s going to come. It’s a looming specter over her whether her own brain is going to implode under its own power. At the very least extended use will leave her with severe migraines, at most her brain will destroy itself.
The ONLY power she has that comes with no double edge is her telekinesis and she tends to actively rely on it more heavily than her other powers because of that.
Ace has a large trove of very strong powers to pull from, but most of them come at a heavy enough cost that now that Ace has the choice of whether to use them or not she just doesn’t.