A new emotion sparked through Anstra’s being as his eyes widened with fear. The news was much worse than he had imagined. These souls had escaped; they were free, and that meant that… they would return to their bodies. They immediately posed as a threat to everything he had work towards.
The mass of papers and books, which crowded the desk, rattled with fear.This would read better as "The mass of papers and books crowding the desk rattled with fear.
It landed silently on the ground, ruffling it’s feathers fearfully."It's" means "it is." You mean to say "its." Counterintuitive, I know, but true.
The angel lifted his head, his shimmering white eyes sparking with steady fear as spoke.I think you mean "...as he spoke."