is it possible for regen to be OP?
You cannot be serious.
Warriors can get high regen. Sadly they just generally suck and 1000 hp/sec won’t do much when you get burst down. You can 1v1 bunker forever though.
Im assuming your referring purely to the boon without any other factors. On its own no its not possible for regen to be OP. However when combined with other methods its relative strength increases.
In a fight thats over in 4 or 5 seconds its not worth very much. But if the fight is over the course of 30-40 seconds or a minute or two it can be pretty kitten nice. I have had very long lord room fights in stronghold where I was able to use regen in place of burning my heal skill. But that involved ALOT of kiting/dodgeing/blocking.
In short. Regen alone isn’t OP even with max healing power. But when combined with other factors (passive/active mitigation and time) its usefulness increases.
The builds that get the most out of regen will be those that can maintain it and have it actually healing for long periods of time and are actively in combat for that period of time.