Pssst- Fiorella "Rook" De Riva was cautious of Lucanis when they first met but not for the same reason Harding was.
She saw this man- who's a legend amongst the Crows and is seen as the perfect blueprint for all Crows- and expected him to be like Viago.
She's been away from Antiva for six months, under Varric and Harding's care and guidance, and she was aware that she had grown lax without Viago's strict watch.
She expected to be berated and told off and lectured. But then she slipped and nearly fell off a ledge and Lucanis caught her easily. Instead of telling her off, he shares a story about the time he and Illario had been playing on the roofs of the Dellamorte estate and a sudden raven flying by caught him off guard and sent him down into the canal below.
He told her how Illario had pissed himself laughing as he helped Lucanis out of the waters. His cousin stopped laughing when Lucanis accidentally slipped again and pushed Illario in the icy water instead.
Then another day, he caught her snacking on a half rotten apple and had her sit down to help him make churros. He didn't lecture her about how it's "too much sugar", he just said after the day they all had, they deserved a treat.
When he finds out the reason behind Fiorella's banishment, he goes up to Viago and tells him off- how dare the Talons blame her for doing what was right? How the hell was she supposed to know about the operation? Viago was the one who should have informed her. A Crow of her position should have been privy to such a large scale operation to begin with.
Fiorella never had anyone sticking up for her before.
The Antivan Crows learn to stop gossiping about Viago's Ghost Crow after that point. Even when they start seeing her about, timidly clutching onto Lucanis' cape as she follows him around the market.