So I'm a Spider, So What?, Vol. 12 (manga) by Okina Baba
So apparently, I've somehow become besties with the demon lord and baby vampy, and now we're journeying together?! On the plus side, I did manage to evolve into my Arachne form, and so finally obtained a human face! Go me! But between evolution and our journey, it's kinda hard to level up, so I guess I'd better torture train vampy and her buddy to survive elf-fire...