Can it be used from boxes? Level will be determine by whose boxes it is in. Since there are so many nice items and I dunno what to use, what not.. wasting a slot for an aura is not an option. I usually put all aura items to a box and move it before every fight.
And well... In chapter 7, max level may be 70, so max healing amount is 420/3s and max damage is 700/3s or 140/s and 333/s. Healing may acceptable (for creeps) but damage is not satisfied enough..
Conclusion: I will use if it can be used from a box. And make it heal or damage per sec instead.