Fourest appears fearless on the outside, much less frightened of water than Trent . However, he secretly has many fears, but he thinks that hiding them makes it easier to get Trent to do what he wants. After seeing the other clones and Dipper fight, he held a grudge against Dipper for melting the other clones. Ever since then, he has tried to remove all similarities between him and Dipper, and has gotten Trent to do the same. This is partially why their personalities vary so much.
Fourest loves annoying Mirra as much as possible and ignores her empty threats of getting him wet.