Aang glares at Ed's words. It's clearly not Ed speaking, and Winry's words confirm it. Aang's first priority was to check on Sokka - he was bleeding! - but Sokka ran off to the sidelines with those orders. He'd have to face Ed, especially with Korra throwing herself headlong at the danger.

Shadows. Like Shikamaru? That gave him reason for fear, if the shadows could be used to control people like his. Aang runs up close to Korra in order to keep her covered following her firebending attack and tries earthbending at Ed's feet to trip him up.

"Sounds like it does concern us. Let Ed out!"