Levi growled, raised his foot to kick the smaller figure away, but Armin stood in between him and his target. 

"Corporal! Stop!" He warned, setting a hand on the hilt of his 3DMG blade.

Levi huffed and set his foot down, snarling at Card. "Pest...." he growled.

Armin put a hand against Levi's chest. "Let me speak with him." He turned to Card. "This isn't a disease or a curse, it's weaponry that we made." he tapped on the machinery attached to himself. "It's for protection purposes." He slid out one of the blades from it's holding box. "See?" he said, smiling. "It's made out of one of the most durable mixes of steels and metals."