I say it's false advertisement. They say in the title it's about an alchemist, and then the guy does anything but alchemy for the whole episode. And no, I do not consider smelting iron sand into an ingot alchemy, even if magic is used for that - that's still blacksmithing. If you want proper alchemy go watch... I don't know, Isekai Yakkyoku, perhaps? And if you want cure spiders, there is a good anime about a nerdy one, that is probably better, too.
