[Kantoku]

Spoiler for Before she clawed her throat out + other thoughts:

She cut her neck open before clawing it with the knife in the VN, didn't she? She might've just done that to make herself bleed to death quicker, not by trigger to L5. Also, doesn't / shouldn't Rika have immunity to the parasite? Her blood was used to make Satoko's medication, after all (though, I'm not sure if that guarantees complete immunity or she simply has antibodies that help slow the effects of it). I'm taking the rampage bit as she simply rage-quit over the situation in some worlds; if she remembered them, they might have been some of the first few worlds she went through when she still had some will to figure out how to exit the maze of Higurashi. Though, since those who have went on L5 rampages left strong impressions on them in later worlds like Minagoroshi-hen, the possibility isn't eliminated...

...I think I'm just rambling, sorry about that