Edward Elric ..

The bond between these two brothers is as strong and hard as the steel of Alphonse's armor and Edward's metal arm. Not only that their souls and blood are connected, but these two suffered the same amount of hardships as they both overcome their own weakness.

Alphonse Elric To Alphonse, Edward is his support and is someone he can count on. He trusts his older brother with his life and knows that Edward would do anything for him. He thinks highly of his older brother not just with alchemy talents, but with their decision making. He supports his brother a lot, and more than that, Alphonse would protect his older brother's life more than his. As much as I have said that Alphonse is kind, Alphonse is straight-forward towards his brother. He would tell Edward straight ahead if his decisions are wrong or if Edward is making a mistake.

In volume 2 of the story, Edward with Alphonse was hunted by a mass murderer named Scar who's targets are all State Alchemist. Both young brothers were overpowered by the vengeful criminal and Alphonse's armor was almost destroyed in his effort to fight with Edward. Edward's right arm automail got busted as well and was weak and powerless because he couldn't use alchemy with only one hand. Edward thought that he was the only person that Scar would like to kill so if he gave up himself then there is a chance for Alphonse to survive. Alphonse screamed for his older brother's life knowing that it is the end for them. Luckily, they were saved by their commanding officer, Roy Mustang, and his men.

"Alphonse: When there's a way to survive and then you choose death, that's what idiots do!!
Edward: Don't talk that way to your older brother!
Alphonse: I'll talk to you however I want!"

After Scar had gotten away, Edward went to Alphonse to check if he was alright because Alphonse had gone quiet. Alphonse punched his older brother and called him an idiot for giving up the will to survive just so he could save Alphonse. Alphonse proclaims that between the two of them Edward must live and save innocent girls who are victims of bad alchemy. To Alphonse, Edward still has a chance and is angered by the fact that Edward chooses Alphonse life over him. As a matter of fact, to Edward, Alphonse's life is more important to him than anything in the world. Edward would give up his heart and life just so Alphonse could live a happy life. That's how much this two are bonded by each other.

Alphonse is passive and relatively patient because it compliments his older brother's brute and rough personality. Alphonse takes over as Edward's personal referee whenever Edward is fuming out of anger and wants to pick a fight after being teased with his height. Most of the time, Alphonse takes good care of his older brother. Like telling Edward to drink his milk to grow older, fixing his bed, tugging Edward's shirt down because Edward likes to rub his belly when he sleeps. Telling Edward to be careful and not to hurt himself. Alphonse is the only person in the series who could compliment Edward's personality.