There is this thing in the world called character development. Sometimes it goes in a positive direction. Sometimes it goes in a negative direction. Often times it depends on the perspective of the person playing the game (or reading the book, or whatever). But whether or not someone likes the way a character progresses has no bearing on the fact that it happens.
It’s obvious in DA:A that Anders cares desperately about the plight of the mages, especially if you’re an ass to him. He rolls with the light hearted humor and lack of responsibility to shield himself, to live his life in a way he can enjoy because freedom hasn’t come easy to him and he plans to enjoy every last drop of it.
But this is where my favorite part of the character comes into play—Anders is a pretty powerful guy. He’s a strong mage. He survives the Harrowing and the Joining, but he’s been made to feel powerless by an oppressive system. To quote Alice Walker, The most common way people give up their power is by thinking they don’t have any. He hasn’t exactly had a stable life, considering he was pulled away from his family to live in an organization with no privacy and spent a year in solitary confinement. On top of that, he finally has his freedom, but his friend Justice keeps bringing up how he should do more, how it’s injustice that he’s free while others aren’t, and while he tries to blow it off, he can’t let it go.
So, he and his friend make a decision that ends in Justice smelling a lot less like rotting, dead ass. Is it a rash choice? Yes. Is it driven by Anders feeling like he’s powerless to change deep-rooted institutional oppression because mages are treated like less than human, and fueled by a lack of personal stability? Yes. Contrary to what a lot of people tend to say, you can’t really find a real world parallel for the mage issues in DA2. There is no Rite of Tranquility, where you get zapped and lose the capacity to think for yourself. Despite what some people may believe, homosexuality doesn’t have anything to do with demons. Mages don’t have the option to peacefully walk around outside of the Gallows with picket signs, and if you look at every single protest and expect that luxury, or think every revolution went down that way, then you are looking at things with a pretty privileged mindset. We don’t live in a world where someone who is pushed down and made to feel powerless by systematic oppression is offered the option to fuse with a powerful spirit, their friend, and work together to bring change to other people in their situation.
A lot of people have talked about Anders’ progression better than I have, but it is really not some kind of enormous jump where the two characters don’t resemble each other. There’s still some humor there through more than half of the game, especially if you’re on his good side. If he moves in, Bodahn says how nice it has been to have Anders staying in the Hawke estate and Sandal comments on how funny he is. He’s more resolute and unwilling to attempt to look the other way at problems that don’t concern him directly as a self-defense mechanism anymore. There’s also the extra passenger, obviously, Anders says himself that Justice takes over when he sees things that always upset him but he felt unable to do anything about.
tl;dr AWAKENING!ANDERS = DA2!ANDERS, THEY ARE THE SAME GUY. It’s fine if you don’t like him, but that doesn’t make Anders two separate people.
That’s just it, too. In DA2 he even admits that he misses being that selfish mage from DAO:A we all came to know and love.
Most people would blame Justice for planting and nurturing all those ideas in his head to begin with, but that’s not entirely the case at all. Throughout DA2, Anders makes it clear that he and Justice are of one mind…when it comes to freedom for mages at least, since the Justice side of him sees Hawke as a distraction if he is romanced.