So after replaying this questline, I've decided that my least favourite quest character is Karliah. I straight up don't like her. I mean, she basically forces you and Brynjolf into the nightingales without even asking, claiming its the only way to defeat Mercer Frey without explaining why. She's too forward. From a role-playing perspective my character would probably be thinking "Wtf is going on?" just like Brynjolf in the Nightingale Hall repeatedly saying "This is enough to make your head spin eh?"
And in the thieves guild she makes YOU come with her to face the guild. As an adventurer in an RPG you obviously are the one to do everything for everyone but i feel they made her dialogue in a sense that she doesn't give reasonable excuses for you to do her dirty work.
AND finally at the end of the questline, i have to go return the skeleton key that SHE failed to protect. I paraphrase her, "I am too scared to face Nocturnal after failing to protect the key." Well for crying out loud you lost it.
What is your take on this? Anyone else care to agree or disagree? I'm curious as always.