If there were words I could have spoken to soothe your breaking heart, I would have said them; however, all I had at my disposal was alchemy. I fashioned you a son from the broken body that lay before us, and when I realized what we had done, I walked out into the cold night. It wasn't in me to sin like that.
I couldn't live with what we had made. I drifted from body to body through the years, trying to forget, but you followed me and brought along new children. Even though I had left, our family had grown. It surprised and disgusted me.
Please know that I never hated you, or our son. I never wanted to hurt either of you. You might not believe me now, but I swear it's true. It's just that sometimes, there are things a person can't remember – not because they aren't able to, but because the act devours them. There are wounds so deep that love cannot hide their scars.
Know that Tricia was not your replacement, except in name. Neither Edward nor Alphonse was born to usurp our son's place in my heart. The truth is that after all that time, all those bodies, it was only with them that I could begin to move on. The Elric family was my way of reconciling my sins with God, and with myself.
As with everything I've done, I realize that this is too little, too late. What damage I wrought by recreating our son has been multiplied ten-thousand fold. So much death has come from trying to save that one life. If I could go back and stop myself from finishing that one transmutation, I would; I've spent the last four hundred years looking for the words to ease your pain, and now I know that I could say them.