Arthur Watts/Affiliation

Salem's Faction
Arthur Watts is a member of Salem's group

Salem
Not much is known of their relationship, but Watts appears to be loyal and respectful toward her.

Leonardo Lionheart
Professor Lionheart is Salem's mole in Mistral, and a important pawn in her targeting of Mistral. Arthur serves as the representative of Salem to Lionheart. Watts currently appears to treat Lionheart with civility but also occasional playful condescension.

Cinder Fall
He appears to look down on Cinder after she was defeated by Ruby. He greatly enjoys tormenting and angering her, especially since she is unable to talk back following her injury. Given his comments, they apparently had a preexisting rivalry prior to her injury as well.

Emerald Sustrai and Mercury Black
Watts treats both Emerald and Mercury with disdain, derisively calling them Cinder's "posse".