The blonde in the beginning was the reincarnated 'hero'
Our heroine (as it was somewhat hinted at not only in the first life, but the decedent in the second) the reincarnated 'scarlet witch'
Thor is the reincarnated demon king (through a process of elimination, also his physical traits match the typical manga demon king)
the friend (who i kind of don't like already) of the ml in the first life is/was the reincarnated 'white sage'
- they were all killed as the blonde dude uttered the word "maydare" when he killed all of them on the rooftop
whether or not their first life times were truly 'evil' like the story will be a mystery for now- it could be one of two things:
1. they're stories were retold to blacken their image
or
2. they were evil (but somewhat atoned in their second(school/previous) and third lives (current/now)