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.
Acquire all Kol's armors.
Discover the secret of Contemplation.
Wear each relic once.
Defeat the brute near Vagrant's Rest.
Wear the Umbral Veil.
Take a ride in Eila's barrel.
Acquire all lanterns.
Defeat the Elder Dark Sissna.
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 Vorsa's journey.
Complete Eila's journey.
Construct all houses in Vagrant's Rest.
Complete Jokell's journey.
Untangle Sissna's weave at the Palace of Lathyrus.
Hunt a roamar.
Defeat the Elder Dark Riak.
Unlock all crafting specialities.
Travel the shadow pathways.
Defeat Touma and Souma.
Meet Kol the wildman.
Defeat the Listener Matriarch.
Free the Diasora pup.
Hunt a squork.
Defeat the Elder Dark Ukkoto.
Hunt a rafet.
Hunt the corb near Vagrant's Rest.
Hunt a Deer.
Claim Vagrant's Rest.