The only difference is he isn't almost immortal in lifesteal gear. Mine was originally for CB but I have since changed teams. This is just some basic gear I tossed him in to test... something.. can't remember what though.
For masteries you'll need to decide what you want to use him for, he has a few different set ups.
Geomancer does great damage for me all over the place. I did lose ground in Spider after his passive healing went away but I went back to using my Zephyr Sniper as the tank and it's fun to watch all the spiderlings proc-ing huge hits on the big spider. In Nightmare Demon Lord he's doing slightly less damage than my Frozen Banshee but she's got revenge accessories + counter-attack masteries and he's in the support tree since I wanted to get a chance to extend his debuffs. Since we have the free reset I'm thinking of switching back to defense tree to get retribution for extra War Master procs which hopefully would add damage and keep him alive longer... he dies a few rounds before Frozen Banshee right now.