Sylvester is a boy deeply dedicated to research and his occupation (psychology) and discovering new things about epithets. He's isolated himself from others (growing up without any friends,) and tends to act snarky and push others away. Under his standoffish exterior, he's very caring and wants someone to talk to. Along with this, Sylvester has a tendency to feel that he's always right, and gets into a lot of arguments because of it. This also allowed Mera to trick him into working for her