watashi ika no
ningen shika inai toiu
kono kuukan wa warukunai ga 私以下の
人間しかいないという
この空間は悪くないが
This space [in which]
[there's nobody better than me]
isn't bad, though.
Note she's saying it "isn't bad." She isn't saying "it's good." In other words, it's not something she really wants, but it will suffice.
watashi ika no ningen 私以下の人間
Humans equal-or-below me.
Humans lesser than me.
People worse than me.
...shika inai ～しかいない
There's nobody but... [humans lesser than me, in this place.]
