He's Just a Necromancer, How Could He Become a Necromancer?

Roger traveled to a different world eroded by the scarlet tide and became a useless undead apprentice. During the life-and-death fight, he awakened the necromantic fusion system. You only need to continuously collect rare materials to fuse legendary equipment with entries and summon legendary undead creatures. [Rusty Iron Sword] + [Unknown Creature Leg Bone Full of Teeth Marks] →Success: [Bone Heavy Blade] [Human Skeleton] + [Leather Armor Stained with Unknown Liquid] + [Rotten Iron Pieces] → Great Success: [Heavy Skeleton Guard] … When the Scarlet God came, the Federation collapsed and the world became a purgatory. Roger calmly opened the fusion column and threw in the [Evil God Head] he had just hunted. [Undead Dragon] + [Evil God Divinity] = [? ? ? [Fusion Preview]: [God-level Creature] [Legendary Arrival] Roger looked at the trembling people and said: "I, the Scourge of the Dead!" [Mixed World View] [Easy and Hot-blooded Adventure]