So i was bored and decided to replay an old save. this time i killed paarthunax (had to close my eyes).

afterwards esbern gives me a dragon blessing and a potion called Esbern's potion. WTF does it do actually?

on the description it says it enables the dragon infuse perk or something. but i drank it and didnt see any such thing in my active effects. i think he's trolling me

I was wondering the same thing, I have no clue what it does

From what ive been reading on other forums about this, the effect is supposed to be a reduction in the damage done to you by dragons (25% reduction). It does not show up in active effects so its hard to test if it works and just doesn't show.

It's bugged -- it is indeed suppose to reduce damage done to you by dragons, but the perk is never added and therefore you can never actually complete his quest. If you're on PC you can add the perk yourself and complete the quest.

Haha me too.

Cheers