Here is the full list of all 34 Ashen achievements.
Defeat the Elder Dark Sissna.
Wear the Umbral Veil.
Wear each relic once.
Complete Flokir's journey.
Reunite the Listener and Human hearts.
Leap into the dark portal.
Unlock all townsfolk outfits.
Defeat the Shadow of the Ashen.
Complete Jokell's journey.
Complete Vorsa's journey.
Untangle Sissna's weave at the Palace of Lathyrus.
Complete Eila's journey.
Acquire all lanterns.
Construct all houses in Vagrant's Rest.
Hunt a roamar.
Unlock all crafting specialities.
Travel the shadow pathways.
Defeat Touma and Souma.
Defeat the Listener Matriarch.
Defeat the brute near Vagrant's Rest.
Meet Kol the wildman.
Take a ride in Eila's barrel.
Free the Diasora pup.
Discover the secret of Contemplation.
Hunt a Deer.
Hunt a squork.
Hunt the corb near Vagrant's Rest.
Defeat the Elder Dark Ukkoto.
Hunt a rafet.
Claim Vagrant's Rest.
Defeat Sissna in the Children of Sissna mode.
Defeat the Elder Dark Riak.
Defeat Riak in the Children of Sissna mode.
Acquire all Kol's armors.