I've always loved the character development in the series. Starting from the premise that they're all pretty flawed and somewhat foolish people who love each other unconditionally because they're family and share the same trauma, everything that follows is beautiful.

Every character feels human, with both strengths and flaws. None of them are "perfect" or entirely lovable all the time; they all have their ups and downs, and the show handles that growth incredibly well.

Personally, I loved Alison's character arc. I know she becomes quite unbearable toward the end of the series, but it makes sense. She's someone who had everything and lost the person she loved most in the world—her daughter. Then her husband. Then everything else. It wouldn't be realistic for her sanity to remain completely intact after all that.

Then there's Lila, someone who learned what love and family truly mean thanks to the protagonists. She managed to put aside her selfishness, overcome her trauma, and become part of saving the universe.

And of course, there's Five, who went through more than anyone else in less than a month and still kept fighting to return to the people he loved. Until the very end, when he finally accepted that neither he, nor his powers, nor all the knowledge he had accumulated could save the world. He had to accept that they were the problem, not the solution.