Reincarnation, in Another World?

Tensei, Isekai? (転生, 異世界?)

A Japanese teenager attends high school where she is bullied. One day an explosion destroys her classroom and kills everyone, but she awakens in a new world, having being reincarnated as a new-born Taratect, the weakest spider monster in the most dangerous dungeon in the new world, The Great Elroe Labyrinth. Quickly escaping from her cannibalistic mother and siblings she realises she has a skill tree similar to hero’s from video games and unlocks the Appraisal skill, discovering she no longer has a name as her appraisal identifies her as “Nameless”. Hungry and unsure she returns to her hatching site and finds her siblings dead or eaten and so teaches herself to build webs. Finding herself increasingly hungry she is forced to cannibalise her sibling’s corpses, gaining the title Kin Eater and unlocking unholy magic. She manages to trap a poisonous frog in her web to eat and continue to level up her skills, but despite her victory the poison scars her body and destroys two of her eyes. Elsewhere in the world it is shown that the rest of her class mostly reincarnated as rich nobility, several even into the royal family, but Fei, Nameless’s bully, has reincarnated as a newborn Earth Wyrm and is now a pet to classmate Shun, fourth prince of the kingdom.