I tried her in a custom game, and am going to want to play her some more, but I want to know some good builds people have seen. I was thinking building her like I do Illaoi (BC, Frozen Fist, mercs, Deadman's, then maybe a steraks and another defensive item), but am not sure what is best. Also, for masteries, 12/18/0?
No one can answer that question because "what is best" will vary from game to game, it's why players have to learn the items to improve in the game and not just copy from mobafire.
For example, your suggested build "(BC, Frozen Fist, mercs, Deadman's, then maybe a steraks and another defensive item)" could be great in one game but be nothing but a handicap in the next.
From what I've seen, she scales very poorly with straight up ad - her ratios just suck. She does however benefit greatly from things like deadman's momentum (she can proc it with her shield :3) which give her that tiny bit of damage that is just enough to fight.
The best build obv 6 zeals
I really like the idea of this build:
Those 675 range bucklers can do up to about 1200 mixed damage and activate a massive gap closer.
Steraks and DD synergise really well with Steadfast presence to keep her alive.
Full defensive Runes, Masteries almost dont matter, Warlords, Thunderlord and Undying are all good for this.
Or alternatively some AD Health build:
