I'm in a March 18 shard as well and I chose Maul for my first zeta and I've been running him as leader now for a while. I average 1.44 in arena and overnight I drop to about 6-11th. He is a blast to play and you can sub a bunch of different sith in for enjoyment. Sure, there are hard counters for him but what team doesn't have a hard counter? If you would like to see how I'm running him feel free to check them out. All I'm interested in playing is sith only in case it wasn't obvious. lol
I run him with DV, zzDN, zSion, SA. I sub in EP and zSavage often to keep people off guard. But Sith Assassin is the real mvp on the team, she is outstanding.
https://swgoh.gg/u/crazygone510/