Possibly the Greatest Alchemist of All Time 3j1g4n
Overview:
Iruma Takumi finds himself caught up in a hero summoning, even though he’s not a hero. Summoned by mistake to Mildgard, a fantasy world of swords and magic, Takumi is given a chance to start over. Though he dreams of a peaceful life, the goddess Nolyn grants him “alchemy,” an ultra-powerful skill that allows him to create anything from holy swords to flying ships. His reluctant adventure begins!