Truth, the smiling smug bastard who made everyone’s life hell in FMA:B.
Or did he?
Let’s start with our favourite kick-ass mother, Izumi.
Izumi opened the portal of truth in order to try and revive her child that she lost in childbirth, and because of her ignorance Truth took her ability to reproduce, unable to have children of her own anymore.
Except, because of what she went through, and her ability to perform highly complex alchemy, she gained two sons. Ed and Al
Moving on to the Flame Alchemist Himself.
Roy Mustang had his eyes always looking to the future. He kept his eyes forward, aiming to be the country’s leader. Truth took away his sight.
Except, with this he was able to remove his tunnel vision and expand his views to see the work that needed to be done in Ishval and devoted his life to it.
The Elric Brothers?
Ed and Al wanted to be a family again, and wanted to feel a mother’s love again, and so Al lost his ability to feel warmth, and Ed lost his leg to stand with his family. They were a broken, incomplete family.
Except, their quest to get their bodies back gave them a family greater than a mother and father. Their family grew to one of huge sizes, whom supported them the whole way.
Truth is one, Truth is all, Truth is God, Truth is the universe.
“[Oswald and Edward] are both outcasts in their own way and in a way that actually complements each other. Oswald is more emotional, whereas Edward is very cerebral and they both have lost everyone in their lives.” - Robin Lord Taylor.
These two characters complement each other so well and they will always end up entwined in each others lives, one way or another.