"But charging her head-on when you knew how powerful she was?" Maybe it wasn't the smartest decision to run, but...

"She could have killed the both of you! You cannot afford to be so reckless, not in a place where we are almost completely powerless and our enemies possess unworldly abilities that we have never even laid eyes on! We can fight, but you cannot waste your lives so foolishly!"

Scar's fists were tightly curled. He was angry because he was scared. People lost their lives in the blink of an eye here, and if that happened to the Elric brothers, he would never have been able to forgive himself.