[@Kessir Tarkin] I'm fine with Geronimo as he is however I'm doubtful that his Apache training would give him the same stealth ability as assassin with their natural presence concealment skill. He'll be good at hiding but if a servant can sense them it won't help all too much. 

i can't judge your main character as he is due to lack of a personality, and backstory which I'm sure is a work in progress. However I'll be carefully looking at [quote] seal spells in the wooden talismans[/quote] part of his magic. As depending on the ability of the spell it could just prevent masters from actually fighting back without resorting to charging their circuits with their magical power.