@Roadrunner9000
One thing to clarify:
The dude that killed his mother was not an aristocrat but an adventurer that used to party with his dad and Rio knows this.
IMO on the Haruto and Rio soul thing:
You can't win against rage. Even Haruto wasn't naive enough to not be cautious against those in the Kingdom.
All in all, Rio was influenced by Haruto's kindness (or more like obsession towards Miharu) and Haruto was influenced by Rio's life experience.