There is an issue right now with the power level of the blade of the serpent favor item returning the ammount of mana that it does, due to the fact the ammount of dps assassin characters can output allows this item to provide a full (or close to full) return to the mp bar of any assassin character, at any level, every 45 seconds as long as they are in combat. 75% seems a bit much without some sort of max mp limitation.
The biggest issue by far with this item though is that it returns damage from skills (not just auto attack) like mines and rain of ice, which are gauranteed to completely restore the mana of any character if used against a creep wave.
While I don't necessarily want to remove the item because it is somewhat unique, in it's current state it is outright broken, and it might be better if this did not work with skills and returned a smaller portion of mp and/or hp or possessed some sort of limitation (like returning at most 50% of max mp).
Thoughts on this?