Wings of Valor by Griz Calderon

Chronicles of the Reaper, Volume II, Story 9: Valkeryth, a majestic dragon born for greatness, soars high above the world with his mate, guarding the skies from atop the tallest peak. As they prepare for the arrival of their young, their lives are changed forever when a threat from below forces them into a battle they cannot win. A story of valor, sacrifice, and an enduring legacy.