Maxwell right now is only "immortal" under favorable conditions. Even then, his version is nothing like his daughter's. Maybe living for more than 300 years has made him senile even after he's changed bodies, which was his previous way of cheating death.
"Let your brilliant, beautiful, cute, smart, extremely beautiful daughter teach you a thing or two."
This is a deliberate taunt that has been intentionally crafted to provoke a misogynist like Maxwell. Laplace doesn't even need to believe whatever she said is true (I don't think she does; hell she even said "beautiful" twice, she's clearly not serious about it), the point is just to get on his nerves in the fastest and most effective way possible. She's trolling him, in other words, and it worked.
The coin being used to create a feedback loop that's preventing him from actually gaining anything is great. A taste of his own medicine. Now he's stuck in that useless state until the magic energy drain on the populace is stopped.