What a weird backstory. Certainly not what I expected. Previously I lamented it's hard to understand what she's doing and why, but this does explain it. If she was a failed, betrayed bottom rung assassin, it's no wonder. It might even explain some of her density. That being said what's the point of having an MC like that? Usually the obvious (and cheap) strength of isekai is that it's extremely easy to sympathise with a modern person thrown into a fantasy world, but now we basically have a fantasy world person thrown into another fantasy world. That's not unique, per se, but usually the person at least has a background useful in some ways. Here, apart from having read the novel, the background doesn't seem to offer anything useful whatsoever. It's just a pile of additional weaknesses on top of Char's original stalker character of poor reputation.