User blog comment:AquilaeAltair/OnS Theories. Third Theory (S3) - The reason of Guren's betrayal/@comment-36009152-20190703020437/@comment-36009152-20190724034201

Good to suggest, didn’t even think of Guren being the one to save Shinoa. As much as we can all hope he, or anyone does rescue her unfortunately don’t see how. Guren like everyone else is largely in the dark concerning super powered demons have possessed someone you know areas XD Unless his plan is forget this, will betray everyone to rescue Shinoa.

In terms of good and evil, Guren is very tricky largely because of his upbringing and what he would do for his goals. Losing someone really close to him in Mahiru, later when whatever happens comes to pass we may be looking back on this and releasing that was the day Guren passed away as well, can easily have that occuring with what has happened so far.

Even more unfortunately it is hard to see that Guren has come to view those like Yu not as experimental weapons but as people. Despite that, and the promises and assumptions like Yu would train directly under his guidance or something, Guren largely left Yu after collecting him outside of Sanguinem. They are both largely detached as Guren’s real world duties of the leader of the Moon Demon Company take over with all the ruthlessness required of essentially an army officer on the battlefield with vampires as well.

It’s related to what good Guren may have in him, would he think it was nice whilst it lasted before casting it aside as duties take over such as his plan. Whatever it is, even though it undoubtedly highlights how good he is to care about fallen comrades and those who fall on the battlefield, it won’t count for much if he’s ready to do something awful on cue.

All debating is off when Mahiru-no-Yo becomes involved as well!

Wrote that but do believe Guren is good, he does care for his squad, shows as well as he can in his own way see that Yu is a person to him now. Just depends whether that inner niceness wins out over a betrayal plan and whatever Guren’s long term goals are, also Mahiru-no-Yo’s feasibly possessing him.