Using the distraction Korra provides, Winry quickly back-steps to get some more distance between herself and Pride without showing her back to him. When she feels like she has a good distance without being completely out of the range of the fight she raises her voice.

"Aang, that's not really Ed! It's a monster using his body, so be careful! Pride uses shadows to fight!"
Honestly she surprises herself with how much she knows. It's a new feeling, but not a bad one. She remembers Ed sitting on the porch steps with her, and telling her about Pride. She didn't get much of the details on how is powers work, or how to stop him, but she knew he was dangerous. At least she had that much she could convey to her friends.