We know that that James Herondale has the ability to turn into shadows due to the warlock blood from Tessa. Lucie is said, by Cassie, to have different warlock ablitites and I have an idea on what they might be. I reached this by looking at other Shadowhunters effected by Angel/warlock/demon blood. 1) Clary has extra angle blood in her veins. Due to this she is able to enhance and create new runes. Clary is an artist, and I think the angle blood acted on this personality trait and gave her this ability. 2) Jace was trained by Valentine to be a perfect warrior. The angle blood then gave him physically enhanced abilities(speed/strength/agility) 3) Sebastian- effected by demon blood the same way as Jace is effected by Angel blood. 4) Jamie who is a shy person. Shown to stay away from other people. He tries to avoid people- literally sink into the shadows. 5) Tessa doesn’t think she fits into her body, wants to change certain features about herself to begin with. Therefore shapeshifting. What I’m trying to say is that whatever blood is in the Shadowhunter it doesn’t randomly give them an ability it gives them one that interacts with their personality. So Lucie Herondale what do we know about her personality. Cassie has told us that she ‘likes to make things up’ and is a writer of novels. This shows that she clearly has a big imagination. As this is the only personality trait we know off I can only guess that her ability is to create illusions- in other words control glamour. (Possibly similar to how Hazel controls the mist in Heroes of Olympus) I think this is a real possibility- as it fits with what we know about Lucie. And follows the same pattern as everyone else effected by Angel/warlock/demon blood. What do you think??? Am I on to something???