How to you get new familiars and how you get to the othermine?

[Drakesonofthedragons]

I have defeat 4 out of the 5 boss that you need to unlock the final boss. I have found both the key and the book from the library of the 3 lvl and also i have free Lillyth.

[LootZ]

Beat the game once to unlock Othermine. For familiars, some drop randomly, some drop after doing certain things (like beating Othermine once, and 3 times in a row)