Full list of all 22 Absolver achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Kill all bosses in their last level with one character
Master all attacks with one character
Create a school
Reach Game Mode Level 100
Open all Cairns with one character
Become an Absolver
Kill Risryn
Kill all marked ones with one character
Kill Cargal & Kilnor
Have Cargal kill Kilnor (or the opposite)
Unlock all fighting styles with one character
Unlock Calbot
Kill 100 Players Character (Any Character)
Push AI off ledge
Become a disciple of your school
Kill your opponent with his own weapon in 1v1
Reach Game Mode Level 5
Win 1 PVP Duel
Join a school
Loot 1 weapon
Kill Kuretz
Master 1 new Attack