I created my own system - Chapter 271 How unfair

“God, please. If you are real, make my one last wish come true. Let me live.”When Callisto got diagnosed with an incurable genetic disorder at age 5, she was expected to live for only ten more years.With her life on its last leg, Callisto underwent an operation that has a one in a million chance of success called the Mutated DNA Fusion, granting her wish to live. However, the operation gave her more than what she wished for.With her black hair turned silver, cat ears overhead, and a tail from her behind, Callisto now has to live her life as a half-human and half-animal, a catgirl.

A polite and lethargic boy was reincarnated in another world as a vampire bishoujo.

Suddenly being able to travel to various familiar worlds, to grow and develop in these various high-risk worlds, you need to follow the following guidelines:

1: If you want to get rich, don’t be afraid of death. If you are afraid of death, you can only eat other people’s leftovers.

2: Don’t always try to save the world, it will be bad luck to be a Virgin in other planes.

3: Don’t let go of good things, maybe you will lose a great opportunity because of this.

4: Don’t wantonly flood your feelings, you can only bring back sadness if you can’t take away the girl.

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- Description from novelbuddy

To be exact, the female lead is an “older sister” type, amid many beauties and handsome guys, she's no white lotus.Also, it's said that the name of this book is the same as a brand of sheep's milk powder.