The Aes Sedai is very still as she considers the implications of this.

"I can see why you abhor it."

To share power with others through a link is far from unknown, but saidar is drawn from outside one's self. Given how Harrow has described the flow of power in her world, it seems very likely that Gideon Nav has risked her very existence for this key.

"You have no Healers?"