The The Forgotten Saga Title update for Assassin's Creed Valhalla has 9 achievements.
Defeat Hel with the Draugr's Toll Outfit equipped (The Forgotten Saga)
Reunite the dead within Kaldstad, Døkkerland and Nidheim (The Forgotten Saga)
Defeat Nidhogg without using an Elk Shrine (The Forgotten Saga)
Complete all encounters in Dókkerland (The Forgotten Saga)
Knock 10 enemies off of ledges using the Kick of Tyr Ability (The Forgotten Saga)
Find Hel's Majordomo (The Forgotten Saga)
Buy all of Nar's Favors at least once (The Forgotten Saga)
Defeat Hel, ruler of Niflheim (The Forgotten Saga)
Return to Odin's Camp for the first time (The Forgotten Saga)