Reincarnated as a Skeleton: Starting with the Necromancer

[Necromancer + skeleton protagonist + game + no heroine + summoning + establishing territory + farming] When I woke up, I became a skeleton soldier in the Boneyard Wilderness! The fire of the soul swayed in the empty eye sockets, and the rugged bone claws held the rusty shovel, but the system panel lit up in this dead silence—— "Bury hundreds of corpses and reward the Necromancer inheritance!" Others travel through all-powerful times, but I want to be a scavenger in the fantasy world of the West? It wasn't until the bottle of green potion fell into the crevices of my little brother's bones, and the white bones grew into armor, and the spine turned into spears, that I discovered... Every corpse in this wilderness is my arsenal! When the kobold lord is stabbed in the back by me, when the skeleton archer's bone arrow pierces the head of his own guard, when the coffin of the dead swallows the souls of the battlefield and turns into an undead army—— The rocks under the corpse shovel are trembling, and the bone throne is being forged in the sea of ​​blood in the mountain of corpses. But the red warning that suddenly popped up from the system sent chills down my spine: "Conquer the mythical undead within thirty days, otherwise your soul will fall into the abyss forever!" Looking at the remaining space in the contract column, I tightened my grip on the blood-stained lord badge in my palm. This time, I want the gods to hear the roar of the resurrected bones!