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