Taking everything into consideration, who is more likely to get the first hit?
Cyclops has a near perfect aim but he DOES have to aim at a flying object and if Johnny were firing back at him, it would be easier for Johnny to dodge Cyke's shots being that he is flying and unbound by gravity.
So I think that nova blast not included, Johnny has a better shot at getting the first shot. He could also confine Cyke to a certain point if he created a high enough firewall perimeter, at least confuse him.
The reason I lean toward Johnny is the flight advantage. If he flew around and dodged long enough to build up a supernova blast, Cyke would be reduced to cinders. If Cyclops caught him with a strong enough blast, then theoretically it might be able to take him out of the sky or something. It's hitting him that's the trick.
-AC