Not all Isekai is Human

This is the story of the last survivor of her race, who is offered the option to be reborn in another world to continue the fight against the monsters that consumed her species.

The new world is a horrible death world. It is filled with both beauty and horror, strange sentients of various types and perhaps the most dangerous monsters ever conceived. 

Humans.

Two aliens. two violently opposed cultures. Is One little world big enough for both of them?

First note: Please don't expect immediate action and slaughter and sex. There's a lot of conversation, drama, and interaction, as she learns about her new world.

Second note: This is not 'humans as monsters'. It is more like "There are monsters, but humans can make their own". Technically I guess it qualifies as a system apocalypse, but it never really hits the apocalypse parts.

Third note: This IS a Litrpg and the 'classes' provide some superhero-style action, eventually. It isn't strictly superhero, though. a lot of bits are contemporary fantasy, some are pure sci-fi, and some are superhero, depending on how people choose their new abilities. The overall theme is technically sci-fi, but soft like a baby.

Fourth note: there is some sexuality (not sex) involving a protagonist in a 17-year-old body. Her mind is over 50 years old, though, and the body was created at that age in order to give her 6 months' leeway to learn to be human. This is not juvenile sex stuff, as the character is fully adult, just not adult as a Human.
Plus it's mostly included for humor and alien context.