Derek thinks Rean is an amusing kid and he also really appreciate Rean for helping him with the vomiting slugs incident. Brownie points for Rean! Derek does think Rean needs to loosen up more, though he is probably not going about it the right way. He is interested in how Rean's magic works and does plan on asking him about it one day. Overall, a good impression that leaves Derek open to getting to know him better.