If you have a snow globe from a guard and use it with helm of hades the following happens:
1st it doesn't update and you have to drop and equip the globe again in order to work
2nd it doesn't update if you remove the hades helmet meaning that those that are already out of range still give flat dmg
Thanks for reporting, I will look into it.
I think the problem is that the guard aura is made for towers (which has some performance optimizations) and is now used on an item. But I'm not entirely sure that this is the problem.
Will keep you updated once I found out more.