Clevatess: The King of Dark Beasts, the Baby, and the Undead Hero, Vol. 1 by Yuji Iwahara

When the King of Hiden sends thirteen heroes to vanquish Clevatess, the powerful King of Dark Beasts dwelling on Luna Mountain, the greatest of all monsters rises to meet the threat to his domain. After effortlessly dispatching the heroes, Clevatess directs his wrath upon their kingdom, resolving to dispose of any peoples who might one day turn against him. In the rubble of his rampage, the beast hears a crying baby, and a dying Hidenean begs him to give the child a chance to prove humankind deserves to survive. The proposition is intriguing, but the Beast King is hardly equipped to raise a baby. Raising the dead, however…