Anyone knows the answer to this or have tested?

If you have oak sage up, when you get hit by a spell that kills both the oak and dmg you at the same time, for example a fireball. Does the dmg you take from the hp total with the oak sage bonus or without the oak bonus?

Im calculating. brb

*Replies after 18 years..*

Your life plus sage bonus

I have calculated this.

Yes.

I don't know the exact answer to your question, but I have seen slow mo videos of souls lightning killing off oak, and then the same bolt kills off the druid, who's hp definitely dropped down.

This was hc too lmao

It would make every difference for even a 1 frame difference in calculations, it should always be the case that if you take damage on a later frame, the max HP buff is gone
but on the same frame? never seen it tested
in pvp it isn't too obvious because most 'simultaneous aoe' that could kill oak would also be absorbed by cyclone armor on windies anyway, negating any benefit of oak. It would matter more on fire druids and/or summoners.
But now we also have some aoe like abyss that could be relevant

It would be easy enough to test with 2+ people, using no cyclone armor, teleporting in place to stop oak from wandering or test in act 4 on a tiny island in outer steps perimeter (not sure if oaks will just fly away anyway, maybe the case)
then any aoe spell should do it, meteor probably best but it has some flame dps, warlock apocalypse would be #1 choice