Hey superpeewee - welcome to the community and thanks for the post! There are quite a few erebus builds in the demiod strategies forum. I really think you'd enjoy this one http://forums.demigodthegame.com/362319 as it makes erebus very hard to hit even when he's not in mist.
no its not
i tested several times and the dodge doesn't really occur that much than you 'd expect
and getting more than 1 point of mist , I think its just waste of points. Bloody haze, really didn't find any good for level 15.
I tried this build on multiplay and i found that it is very weak against health-stacked erebus.