There is no escape from the slave catcher's songs

when you're standing at the crossroads, don't know what path to choose, let me come along cause even if you're wrong

So I want to do a little analysis on Angeal. These are my interpretations of what happened, as the Ultimania books don't give up any further knowledge on Angeal, other than Project G and his age.

After the mission to Tamblin, Angeal disappears with Genesis. Angeal must not have know about his past, considering after his offstage talk with Genesis, he leaves behind his duties as a SOLDIER without saying a word to anyone. When we see Angeal again in his hometown of Banora Village, he has left behind his Buster Sword at his Mother's house and gone off with Genesis. I think this is a very important fact. Angeal always had his sword with him, safely strapped to his back, never used and certainly never left behind. Angeal uses his sword only twice. Once to save Zack's life, and the other to break up the fight between Sephiroth and Genesis. So this sword is dear to him, he would have only left it behind if he felt he no longer went with pride.

After his mother's death, Zack thinking that Angeal himself killed his mother assaults him, knocking him down to the ground. Angeal doesn't even try to fight back. Nor does he refute Zack's accusation that he killed his own mother. Earlier, his mother mentioned to Zack that Angeal wrote her regularly, so the two had to have had a close relationship. And she had lived all those years, apparently hiding the truth from Angeal, so when she realizes that he has found out and how the truth has broken her son down, she kills herself. No doubt Angeal must have felt some guilt over his own Mother's death. This is more than likely why he doesn't clear up the misunderstanding, when Zack accuses him of killing her. Just the way Angeal has his head hung down, it's very unlike the firm, strong Angeal that we witnessed at the start of the game.

When Zack meets Angeal again, this time in Midgar, Angeal is completely different-- he's cold and angry. The same thirst for vengeance that burnt at Genesis now burns within Angeal. He reveals to Zack the single white wing sprouting from the right-side of his back. This snowy white wing and the downpour of white feathers the rains down when he unfurls his wing is clearly revolting to Angeal. Human beings shouldn't have wings. I've become a monster. As a monster the only thing I want is world domination and revenge. Not too long ago, Zack would have agreed, had someone not told him that they thought wings were a symbol of someone who desired freedom. He disagrees with Angeal, telling him that wings are the evidence of an Angel, but Angeal angry replies to him IF I'm an Angel, then what should I want? What dreams should I have?!. Having had enough, Angeal demands that Zack fight him -- Zack smiles sadly and shakes his head, Angeal punches him in the stomach, sending Zack flying backwards. Zack stands, but still smiling, refuses to fight Angeal. A monster only wants one thing..is to be human, and hurling a Materia spell, sends Zack crashing through the plate to the slums below.

Angeal's desire to fight Zack is from his anger at what he had become and wanting to rid his heart of the people he cared for in life. His mother was already gone, and the only one left to try to talk reason into him, who still believed in him for certain, was Zack. And Zack was refusing to fight Angeal. If he is to be a monster, Angeal wants to be one completely, with no conscious and no one to remind him of what who he used to be. Interestingly enough, he has his Buster Sword. Had he really wanted to, he probably could have killed Zack, but his heart wasn't in the attack. He was angry at the world for what he was, as well as himself, but deep inside the real Angeal was still there and very much confused about what purpose his life should hold, now that everything he knew as truth, was a lie.

Now Angeal is back on track! Genesis Clones are flooding Midgar again and Zack return to Midgar from the slums. On he highway he is met by Angeal who flies in. Though Zack is wary of him, Angeal asks his friend to fight with him the enemy is any and all who threaten the Planet and once Zack agrees, using he wings he hated, he flies off, with a fidgeting Zack, to Shinra HQ. Angeal has accepted what he is, in a sense, by deciding not to let what he is define who he is. He can't go back to being a SOLDIER, but he can still help in the fight, a cause bigger than any conflict with Wutai -- saving the Planet. As if to show us that he isn't the same Angeal that would attack his own 'student', he uses his Buster Sword to stop Genesis from killing Professor Hojo. Genesis, knowing he won't be allowed to get near Hojo, flies off leaving a Summons behind. Angeal flies after Genesis, leaving Zack to fight Bahamut alone, telling Zack I'm counting on you, I know you'll beat it. This Angeal is so much more upbeat. I had thought at this point Angeal was okay with what he was and could continue on this way, but that was only a false hope...

Angeal tells Zack that he was the one who should have taken care of Genesis, and that he now has a job only for Zack. Hollander comes out, a jerk as always, and reveals something that Angeal obviously didn't know -- that he is Angeal's father. Of course, Angeal doesn't want to believe anything like that. Implying that he is aware of Aeris, Angeal sort of taunts Zack with You have someone waiting for you, don't you? and reminds Zack of his promise to protect the Planet. He then summons his clones to him and becomes Angeal Penance. A fitting name penance - a punishment undergone in token of penitence for sin. Zack defeats him, but I think that using his powers that way caused such severe deterioration that there was no one Angeal could have survived. You did well Zack. I leave the rest to you. Never let go your pride. He passed the hilt of the raised Buster Sword to Zack. Angeals face is completely at peace and he is obviously proud of Zack. He heaves one final sigh-- and dies. It was the nature of Angeal's relationship that he wanted to be the one to stop his dear friend Genesis, and it is the nature of his relationship with Zack that he wanted Zack, instead of someone like Sephiroth for example, to end his life. IT is the ultimate request to make to someone who is dear to you. And to most it is horrifying, most people are raised to believe killing is wrong regardless of the circumstance. Angeal saw his life as something that could, in time, threaten the Planet. Or maybe he just refused to accept what he was. Regardless, it was cause of unhappiness for him, something he simply could not go on with, and he was asking for mercy from a person who he knew well, could trust, and maybe saw some of himself in. This was the young man he was mentoring and imbuing his doctrine of dreams and pride into. Even if this request would cause Zack pain, it was that strength that Angeal needed from him more than anything.

This is purely my opinion, so I don't want anyone reading and thinking it's the gospel truth. In Advent Children, Aeris and Zack are able to visit Cloud, Tifa, Marlene, and the Children are sensitive to Aeris' presence. After being in the mansion of the Shinra basement for 5 years as a lab rat, Zack has a vision of clear blue sky above, and the sky being clearly reflected in the water below his feet. A single white feather wafts and marring the water's mirror like surface and breaking the illusion. Zack opens his eyes and before him is Angeal. Staring at Zack within the tank, he turns and walks away I have no need for such a pathetic SOLDIER. Seeing Angeal walk away from him and basically calling him useless, Zack beats at the glass of the tanks, desperate for his mentor to come back. Regardless of what Hojo had been doing to him, regardless of the drugs in his system after five years, Zack finds the strength after this vision. This is how Zack manages to escape with Cloud. It makes me wonder if, from the Lifestream, knowing Zack's predicament, Angeal came to him (as opposed to Zack only imagining him) to give him the encouragement Zack needed to gather the strength and free himself. Zack is a SOLDIER, so he's used to tough love. You don't become a SOLDIER with kind, soft spoken words and someone kissing your ouchies when you get hurt. I'm sure that at no point, Angeal ever babied Zack. We also know the Jenova within Angeal didn't warp him the way it did Sephiroth. And Angeal seems in tune with the Planet, after all he knew the Planet was being threatened. This is why Angeal's wing is white, a sign of purity, uncorrupted by the cells within him. His consciousness is also strong enough not to get lost among the others in the Lifestream. After all, he has someone he needs to watch over.

Zack dies and from the brilliant sky we see someone flying down to him, someone with a single white wing. Reaching down, he takes Zack's hand and the two ascend. Though Zack died seemingly satisfied, the Great Unknown should be daunting for anyone. The final thing Angeal can do for Zack, is take his hand and lead the young hero into the warm brilliance of the Lifestream. As if to say, see Zack I've been with you the whole time.