this is a lot closer than some will think. nefaria has beaten all the avengers and the t-bolts handily, and has proven to be nearly invulnerable and has even stopped thor's hammer. he's essentially a pre-crisis superman. at one time, thor and the thing did pretty well together against thanos, and surfer alone has caused thanos some difficulty more recently. despite all the luv thanos gets on this forum, i definitely think CN is in thanos's weight class - below skygod but above top tier hero. he's also smart, but this is where thanos has the advantage. CN would make it a hell of a fight, but thanos has the experience and the intelligence to eventually take CN down. great match up though!