User blog comment:ElleRose/Cris, the Mana Blade/@comment-4087140-20120612031627

Another idea would be to adopt the effect of Dota's Magic Wand item, which gains charges (when enemies use abilities) that can then be spent to regain health and mana. The effect could easily be reworked into an ability, improving cooldown, restoration per charge, and maximum charges as level increases.

Just a thought.