I will have to reword this later. Couldn't find my muse and had problems trying to convey the sudden jarring change of speech in the reveal without resorting to profanity. Especially when trying to fit the twist inside the first word of the second panel.

Oh silly me, just invent my own! If it works for HK-47, it works here too!

To clarify:
Centipede mimic gurl in her private thoughts talks like Marisa but with ore as first-person pronoun (Marisa noticeably doesn't).
Or alternatively a Disgaea-style maou, almost a toned-down Laharl. She does kinda sounds like an evil overlord wannabe-type too.