I have been told that it should be possible to reset your attribute point…and to be able to do that you need a potion to do it…
Can anyone tell me if that is true and where to get that potion ?
MadnessDK
You get it from Coven faction quest
Each difficulty you get one, and it isn’t from Coven faction quest, you get it from the quest the girl gives you at Fort Icon right after the that cinematic plays to go save her father. When you turn the quest in after completing it, you get a Tonic of Reshaping.
this is great news, i thought it were only once! 
Nemesis Troves can also drop it.