The Skeleton Soldier Failed to Defend the Dungeon is a Manga in english language, Action series, english chapters have been translated and you can read them here. You are reading chapters on skeletonsoldierfailedto.com fastest updating comic site. The Summary is
The Skeleton Soldier has only one goal: to protect its beloved mistress, Lady Succubus, from any harm. Unfortunately, it fails miserably when a group of invaders storm their dungeon and kill them both. However, mysterious circumstances cause the Skeleton Soldier to be reborn 20 years in the past, giving it a second chance at life and to alter its destiny. As it struggles to gain new skills and abilities, the Skeleton Soldier acquaints itself with the world and unfamiliar companions. It embarks on a journey to achieve ultimate power, all for the sake of shielding its master from the tragic fate that will befall her. While seeking to uncover the dark conspiracies of the different factions residing in the world, the Skeleton Soldier might also step closer to unveiling the secret of its own existence. [Written by MAL Rewrite]