@endiness // You’re quite right with everything you said actually, but here we have two different points of view. I’m not saying that Castiel is a monster, actually I am rooting for him and considering him as a hero myself.
However. Castiel did stop the Apocalypse for Dean, he wouldn’t have if he didn’t have this talk with Dean in season 4 saying it was the right thing to do to help Humanity keep Lucifer in the cage, he wouldn’t have done it if he hadn’t dragged him out of Hell, he wouldn’t have done it if he hadn’t been liking him first.
While he did a lot of wrong to Heaven, yes he also tried to make things right. I know he was protecting himself most of the time, I know he’s always been loyal and that he still is now, however, there was a reason Heaven and the angels stripped him off his soldier status.
While the angels didn’t know about the Apocalypse, I believe a lot of them knew they were about to let Lucifer out to finish the plan, not particularly to start the Apocalypse, but actually to stop it by killing him first. This is God’s plan, not the Apocalypse, after all, and it was I believe the whole plot of season 4.
Castiel was always a defective angel, it’s said a lot by Naomi who kept brainwashing him and setting him back to factory settings to make sure he wouldn’t feel too much for other people, and in a way, yes, it makes Naomi a monster too. However, there is multiple ways to see all of this:
The first would be your way, go with humanity and see things from there. Castiel did a lot of good, he keeps doing a lot of good, so indeed he is a good person. I actually agree with that. Castiel is, in my eyes, a hero, he keeps saving the world with his friends and wouldn’t stop even if it means he has to die for it.
The second would be to take everything in consideration. Heaven, Hell, anything in between. The overall. It would make Castiel someone in between. Not that good, since he murdered a lot of his siblings anyway (even if it was self-defense for most), but not all bad because he saved a lot of people on another point (humanity, basically, and Heaven after the civil war). It would make him a truly neutral character.
The third would be the last one, and go with Heaven, their beliefs and what is implied from it. Heaven is an army, it’s a lot of soldiers created with the only point to fight their own wars and care about their own plans. Armies have a special way of taking care of things: don’t think, don’t try to figure things out by yourself, obey orders, don’t disobey. Don’t think because it’s what gets you killed, don’t try to figure things out by yourself because it’s teamwork and obedience that will help you, obey orders because “higher ranks will know better”, and don’t disobey because it makes you someone “bad”. Heaven being an army, in a technical way, every angel (soldiers) agreeing with Raphael (an archangel, so kind of like their commandant) had a reason to do so: they had to obey orders. On this point of view, Naomi is just an obedient soldier, Raphael’s followers are too, but Castiel is not, and that gets him to have this “monster” and “pariah” outlook. Makes him the one to shoot down.
Now I never said anywhere that it was my opinion. I am looking at it all trying to be neutral, trying to be inbetween. Angels can be scared of Castiel, Hannah showed she was when we met her with the horn of Gabriel (I believe), angels can hate him, angels can think what they want of him, it is all just my beliefs, but I do not think before this episode in season 14 that anyone really forgave Castiel for all the murders (which led to Heaven’s state) and hurt it brought to them.
To me, however, Castiel is indeed a hero. I won’t say he’s a good person, he is for sure but not enough for me to call him this way. He’s too flawed, too human to be, and while he did mistakes, on my point of view, he did them for a good reason. However just remember:
Your monsters might not be someone else’s monster. My own monsters are the people who hurt me before, even thought it made me stronger, but they are not yours. Castiel might be Heaven’s monster, but he doesn’t have to be ours.
Your hero might not be someone else’s hero. My father was my hero, but I do not believe he was yours. So on that point, Castiel might be a hero for a lot of us, but I don’t believe he was to heaven.