Too much damage, combined with utility. Narrow your focus on certain spells as to whether their purpose is to damage or set-up enemies to be hurt by your spells/allies. Why don't you include the hero's attack range?
Attributes: Growth is too high for a hero with a built in regen/physical damage block spell, other than that fine. I can't say much more without knowing the hero's range.
1. Deals too much initial damage for a DoT spell/a spell that possesses a secondary damage component. The fact that you take bonus X damage whether you don't cast a spell or not, makes me wonder why you added the component.
2. CD needs to be much higher, maybe 30 seconds or something; the radius should be static, maybe 900 at most, since most people will try to skill him as 1, 2, 1, 3, 1, 6, etc.
3. Ranged hero with a healing spell, that has 360 cast range? Why? Scaling is probably off for the heal and the opposing team should be able to purge or remove the buff.
4. Really high damage nuke, even without the OD component, not to mention the slow. Reduce the damage, since it has the missing mana component, and scale the slow.