These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Angst Dissonance: Although his tragic past gives him some leeway, Teito constantly moans about Mikage's death every single episode/manga chapter, even though he's been reincarnated.
Angst? What Angst?: after having had his country invaded and everyone he knew, including his adoptive father, murdered while still a small child, being made a combatslave and forced to kill people daily for training during years and seeing his only friend die after having been possessed by the man who killed Father Teito Klein holds himself remarkably well. He still angsts a lot but who wouldn't in his place?
Draco in Leather Pants: Ayanami. Yes, he did kill Mikage, and try to ruin Teito's life, but he still has a very large fanbase. He's even more popular than good guy Bishops Castor and Labrador.
In the minidrama "Escape," Ayanami is featured crossing paths with Teito and Frau, "making a serious love call" (as Frau jealously puts it), declaring how he and Teito "cannot live without the other" after a process of quiz show fanfare.
Marty Stu: My God Teito, even the fans agree; Tragic past -check, lost memories -check, secret royalty -check, God-like power -check (he controls the eye of Mikhail AND is Pandora's box), The fact that every character in the series seems to want him -check, the fact that he is constantly labelled as having a pure soul despite the fact that he has murdered -check... The list goes on!
The Woobie: Teito. The tragic life of a slave, being forced to kill for a living, the fact that everybody wants him, the deaths of his biological father, the man he knew as his father, and Mikage the God-like power that's inside his body, and NOW we learn that the reason Ayanami needs him is that he is Pandora's box