Martian Manhunter handed Nova over to Teddy but it was only so he was in a better position to get to work. He gestured for him to relocate back down on the ground and they moved back down together.

We're not going to be able to remove him without a fight, Osborn won't give up a chance to obtain the Nova Force and the Xandarian repository of knowledge easily, said Martian Manhunter to Teddy telepathically. I'm going to have to attempt repairing his mind right here and now so that he can refuse to be taken against his will by the Avengers. Be prepared for him to make any sudden movements.

"One of the world's most powerful telepaths," J'onn answered simply, in response to Osborn's question.

He reached out his hand again, holding it over Nova's face, closed his eyes, and with that simple gesture it was already too late for the Avengers to take advantage of Nova's mental state.

"The Xandarian Worldmind is an organic computing matrix, and though it was difficult, it wasn't immune to my telepathy. I've just helped it do the organic equivalent of a cold reboot. Nova should regain consciousness in a few short minutes."

And if he was 100% cognizant and not ailing mentally, he couldn't be taken away.