Who is Perlith from The Hero and the Crown and what is their importance?

Perlith is second sola, the second in line for the crown should something happen to both Arlbeth and Tor. Galanna marries Perlith when it becomes clear that Tor is not interested in her, settling on second instead of a lesser marriage. Perlith is a lot like Galanna, often abusing Aerin verbally because of the rumors about her mother. At one point Perlith attempts to use magic to embarrass Aerin in front of guests to the castle, but Tor comes to her rescue. Perlith is simply a bitter man who resents his place in the hierarchy of the throne and the little girl who is braver and stronger than he.