"Oh, Coco!" Arabel exclaimed when she saw the little fox. She took a step towards her, but Coco instinctively retreated, holding in her paws the Ghost Mask that she stole from Erza's treasury and brought at her master's request.
Coco was in the room from the beginning.
At Idan's request, she couldn't do anything until Arabel took control of her body. That's why she saw everything that happened here in detail.
When she saw how her mistress's hair and eyes were completely dyed in the color she knew, Coco froze in fear, remembering her past. Witnessing what the mistress had done to the young dragon only increased her fear.
Coco began to tremble and, hiding behind the Ghost Mask she was holding in her paws, tried to hide behind it.
Arabel, noticing Coco's fear, sighed heavily.