One side story is from the POV of Lennox, Aeroc, and Kloff's firstborn in the second timeline. Another is about Kloff getting amnesia and acting like a gentleman, causing everyone, including Martha and Hugo, to panic. One has Aeroc meeting the older Kloff from the first timeline in a lucid dream. There's also a Linus x Raphael story in the second timeline, a "what if" story where Aeroc survives the first timeline, and finally, Ray x Linus from the first timeline.
You could say it's toxic. Ray wanted revenge for his mother, so he made a deal with Linus and tried to seduce him. In the end, the whole thing became a complete mess. Ray ended up as Linus's sex buddy, and honestly, I found it really uncomfortable and disgusting.
I thought I wouldn't like the "what if" story the most, but the Ray and Linus one was actually worse. Maybe that was the author's intention, and it's her story, so it's her call, but... I don't know. I'd genuinely rather read fanfiction of Ray and Linus than the original story.
In my opinion, AveryGreenApple and U_A1111 wrote much better revenge stories for Ray than the author herself.

As a novel reader, I don't get it. This is part of the canon novel, right? So why add a hypothetical warning? It's the third timeline, and it's canon. That's weird.