With the shift in the previous episode, Sion and Ryner ended up in quite
the fight against each other. The two have an extensive past to be
certain, but something had changed with Sion that now has him getting
closer and closer to Ryner before he outright attacked him. That half of
the episode was wonderfully atmospheric and had some great animation to
it as it set the mood and launched into the actual attack itself. While
it was a disconnect in why Sion was like this, owing more to events
that have been snaking around behind the scenes for awhile, it's
definitely not something that has been seamless. But that's been a big
way this series has operated for awhile now.
The fight naturally goes badly for Ryner as he's laid out flat, which leads to Sion going through a strong internal confrontation with himself over it as he battles the two sides that are warring in him. It's fairly interesting as it plays out since it runs the emotional gamut a bit with some strong words said on both sides, as well as a bit of flashback material to really highlight the bonds between Sion and Ryner from earlier in their lives. But in the end, it's all about putting Ryner down and he's most definitely that at this point, at least until Ferris comes along later and manages to spirit him away so that they can regroup and figure out what to do.