Because his soul was the same hue as yours. What master doesn't put a touch of themselves in their own familiars?

[ He rubs at his brow with a knuckle. ]

Hythlodaeus insisted on bringing him along, despite my misgivings. They would not speak a word of their purpose until we came across Venat during our tour of Elpis. 'Twas then she marked Rhea'li out for what he truly was: a visitor from the far-flung future, inexplicably bearing her protective magicks.