Yes, I think Crusade can be a good explanation, but following the previous 2 explanations and taking into account the "hardships", it can be closer of an analogy with Christ and his Crucifixion.
Remember Christ's story. Son of God, prophet that came to Earth to teach humans on the Grace of God. But then humans went against him and punished him, made him go through several hardships and then the crucifixion. Ange wasn't an explicit prophet, but she was kind of "programmed" as one, -say with biogenetics or so, and started to live the hardships similar as Christ lived them. She also did miracles (like with Sylvia, and "walking again"). The analogy works except in the point that Ange wasn't an explicit but rather an implicit prophet.
Prophet because you can see in the last chapter where everything gets explained:
First the Prophecies which are inside the songs. By the way, "El Ragna" is a reference to Ragnarok. Quoted from HorribleSubs:
The returning El Ragna. The time flows. Through the hour glass.
The flames of countless lives. Fall through and become stars. They fly beautifully.
And fade away in the cradle of life and death.
The wind goes, El Ragna, with roaring wings.
The light of the beginning. The light of the end.
All the elements of the prophecy happen in the last chapter. The world is dying, and "The light of the beginning" and "The light of the end" fight.
Also added from Ange, being a prophet, -a Messiah like Christ (Also quoted from HorribleSubs):
"I won't let myself be controlled by anyone!"
"Humans are: Anti-authoritarian, aggressive, rebellious misfits"
"I understand now why Normas were born!"
"Human genes will not be controlled by the likes of you"
"Why are Normas all women?"
"So they can bear children to those they love, and so reject your world!"
"Mother handed down the song and the ring to me."
"So I could destroy this rotten world, made by a rotten creator."
Then it comes another part of Fukuda's mock on the otaku-waifu culture, then (also quoted from HorribleSubs):
"It's ten million years too soon for you to even try to hold me!"
And the Prophet/Messiah wins.