Abyss Born, Rise of the White Wolf

Kael, an F-rank wolfless unable to shapeshift, is publicly rejected and gravely wounded by his betrothed Alpha heiress Lyra during his awakening ritual. Left for dead in Black Shroud Forest, he inherits an ancient Lycan royal heart and unlocks a devour-evolution system. By slaying monsters and absorbing Blood Essence, he evolves step by step into a mighty Lycan warrior. When an abyssal beast horde looms over the Pack, he becomes their only hope and awakens his true Lycan form.