I don’t think Kyrie started killing everyone out of anything more than selfishness, but I agree that Kyrie is acting out of character in her final confrontation with Eva, because seriously, if there is ONE character in Umineko where I would consider it absolutely impossible for them to lose because they decided to give a big villain speech instead of coming up with a better way to deal with the adversary, it’s Kyrie. Taking this to its logical conclusion means Kyrie already knew she would lose this duel.
This is why I believe that Kyrie’s gun was jammed or not functional in some way. She did after all fail to kill 3 people with it just earlier (though Gohda does put a wedge in the streak). Perhaps she was also simply out of bullets. Either way, she realized there was no way for her to get out of this alive since Eva was pointing a gun right at her and she quickly confirmed her to have been perfectly capable of killing Rudolf earlier.
So all that stuff she said about not giving a single fuck about Ange was a lie, made so that Eva would feel sorry for her and care for her after Kyrie’s death. Even in her final moments she never lost her cool and went for the best possible outcome. And when her plan succeeds and Eva says she’ll write her into the catbox as having cared for her daughter until the very end, she smiles.
What a brutal irony that even though they were never meant for anything more than to manipulate Eva, Bernkastel ended up showing Ange those cold last words anyways and was led to believe they were true.
If anyone disagrees with this interpretation, tell me, for someone as ruthlessly efficient as Kyrie, was there any reason for her to provoke Eva as much as she did in their final clash?