Hey Gummi! Yeah, sorry for not posting on Crossover Creek anymore, but I went on holiday for a week or so, and then when I came back, I realized it just wasn't worth reading through five books worth of text to be able to post there again ^^
In any case, I'm going to warn you on the whole immortality thing, which is that there's an unspoken rule in HCL that true immortality is impossible. Lots of players in the early stages of HCL created immortal characters that could never be killed off, which is when I introduced Stein, who can kill off most 'immortal' beings by ripping their very essence into tiny shreds and lobotomize the remains. While it's not an absolute rule, all people will have special weapons to take down immortal characters, and no matter what trapping you give your immortality, someone's going to counter it.

To give a quick example, you stated that Fate had determined the point of Kaika's death, and she could not die until then. Now, Hope, a character you met, was created with the ability to rewrite the core rules of the universe to remove such bonds. Some beings are immortal because they are deemed necessary by one of the universe's core forces, and Hope exists to kill such beings by removing their immortal status.

Fair warning has been given.