His best feat as I recall was magnetically holding or moving an entire asteroid belt from a another planet in the same system. Essentially it's like like holding a planet from planetary distance. He's also used his powers to affect things in a very different (and highly unbelievable) level than Mag's. For example using his power to control the movement of air and suck it away from people with sonic powers and suffocate them into unconsciousness because of the "parra"magentic properties of Oxygen and Nitrogen. He's held cities aloft etc etc.
Take it this way, the least powerful version of Cos restrained a bloodlusted mindcontrolled Orion with a gesture and forced him to flee away rather than fight him.
^ You know that leather-on-leather is making the screechiest sounds ever, and ole boy will have a task on his hands removing her seamless body suit w/ futuristic belt