Complex sentence: The Noah frees Allen to rescue him from the Apocryphos, a sentient Innocence that guards the Heart, causing the Order to revoke Allen's rights as an Exorcist and treat him as a Noah.
Split into simpler sentences: The Noah frees Allen to rescue him from the Apocryphos, a sentient Innocence that guards the Heart. This causes the Order to revoke Allen's rights as an Exorcist and treat him as a Noah.