I'm a Lucky Little Skeleton, So What's Wrong with Summoning Humanity's Strongest Warriors?

[Universal Lords + War Between Humans and Demons + Conquest of Another World + Farming] Under the control of a mysterious force, two billion humans and monsters are thrown into the Battlefield of Gods and Demons to slaughter one another. At the beginning, each monster castle automatically spawns five low-tier monsters of its own kind. To keep things balanced, humans are also given one free chance to draw a hero. Gu Lou, a skeleton soldier influenced by the remnants of a human soul, “accidentally” chooses a human castle and gets lucky enough to draw Saber, a Mythical-grade hero. Next, with the help of his incredible luck, he acquires a secondary base: the Great Tomb of Nazarick. “Saber, I hear bathing in dragon blood replenishes the calcium in your bones. Go catch a few and give it a try.” “The Chimera Ants actually think they can outnumber me? Albedo, show them what the Army of the Dead can do.” When the other lords encounter Gu Lou, “Oh my god! Humans have actually allied with monsters, and their leader is a headless little skeleton!”