Tsume Kudaki no Lullaby

In a world where there are clawed creatures that were once human whose souls were accumulated by their negative emotions, causing countless mysterious deaths across the world. Pechika travels indefinitely to find a cure for her half-dead priest named Noru and also acts as a claw breaker to get rid of these vicious monsters along the way. A short one-shot tells a story of how cruel the world is, but also the peaceful and beautiful scenery of an indefinite travel, a long journey to the little light at the end of the tunnel of the characters, and to live boldly.

(Source: MangaDex)