(Twitter thread I wrote earlier and thought I’d reproduce here since y’all seem to like my Eclipse meta posts:) So I've seen a few claims that the reveal about Chadok's relationship with Dika creates narrative inconsistencies, especially regarding Chadok's characterization. Personally, I disagree. Ep 11 has introduced several major plot holes, but I don't think that's one of them.
Chadok's prior relationship with Dika adds extra dimension to both characters, but it doesn't in any way negate Chadok's role as the primary villain of the story. Because while Chadok is a member of an oppressed community and he's grieving his lost love, we know that he has consistently made the wrong choices since his own school days, and he didn't let anything--neither love nor grief--change him. He never removed himself from the principle's influence. He never fully accepted his own sexuality. He never put Dika's wellbeing before his own fear of exposure. And worst of all, he either didn't realize or didn't care that he was pushing his students down the same tragic path that he and Dika walked, and that Akk in particular was in danger of breaking the same way Dika did.
Chadok is a tragic figure, but he brought that tragedy on himself and then pushed the next generation to make the same disastrous decisions he did. He learned nothing from Dika's influence or his own mistakes. He was so committed to the system that everything else, even his own happiness, was secondary to it.
I don't find that inconsistent. Quite the opposite. Chadok has been brutally, painfully consistent since he was a prefect. He's an object lesson in the costs of unreserved compliance and conformity. He has lost everything but Suppalo, so Suppalo is his everything, and he demands that it become everything to Akk and the other students too. If Suppalo's rules and traditions are called into question, he will be forced to question his own actions in her service, and that can only lead to grief and regret.
That's how he can ruthlessly berate Akk for failing to do his duty one day and then cry over Dika's memory the next. He doesn't notice the cognitive dissonance because Dika's death, as painful as it must have been for him, didn't ultimately impact his worldview. His commitment to Suppalo is too strong.