Bat Swarm: Some thoughts
I see two problems that I think should be fixed:
1) Bat swarm is I think a little too good to be getting at level 5.
2) Level 3 batswarm, at level 15, is an almost useless upgrade. 150 damage at level 15 isn't worth the mana cost or point spend.
My suggest is then to change the ranges, as follows:
Level 1: 15 yard range
Level 2: 22.5 yard range
level 3: 30 yard range
Yes, there is no upside to this, and is a strict 'nerf' in the sense that it makes Erebus weaker. While I'm not one to comment on the DG as a whole, I think this one aspect is in need of some modification.