Prospero's reaction to being called out to was a strange mixture of a twitching spasm and suddenly sticking bolt upright, his tophat nearly falling off of his head before he scrambled to catch it and hastily put it back in place. Obviously without the help of his illusions he wasn't nearly as stealthy as he had initially hoped. what followed this revelation was a series of mental and emotional stages, beginning with surprise at being spotted at all, then anger at himself for being foolish enough to get spotted by someone so easily, then just embarrassment as he realized what a fool he must look like sneaking around in plain view, in a rare moment of non-arrogant self-consciousness.

The end result of this was a lot of spluttering, a slight amount of mask-hidden blushing and then angrily shouting "Fine, but you guys better not leave me behind got it!?" then a lot of quickly racing after Naoto and presumably the others while having even less of an idea of how to get to the thunder guardian's house than any of the rest. He had to run regardless given the shortness of his legs, though it at least gave him an excuse for the cape to flutter dramatically as he ran without using illusions to do it.