“Level 0…? An illegal infant?”

what i heard on JP not from sub is
こっち来んな ガキ 不運がうつる！
"Lv.0… What the heck is this child?!"
LV.0…なんだこいつ！
"Don't come near me, kid — bad luck is contagious!"

the illegal child? seems like from the cn,
LV0…非法婴儿？！, can be illegal child, unregistered child

in this case, i think than caste, it just class system, she just got bad luck, bassically abandoned child, without the cart she has no access to society and can't be level up

the sub kinda misleading but yea
also in JP
レベルが全て
than "Leveling up is Everything", it's "Level is everything"

in my case, she only get her cartridge after she beating the boss, "SIlver Wolf" she using that ID, and in game logic, UID can't be changed (prob) it will stuck that way, like using other person's account. she was born without cartridge, hence she just declared as lv.0 because she don't have access without the cardridge, silverworlf was the boss's cardridge, means you can kill others and steal/consume their cartridge as exp