Ultron vs John Constantine

all feats/versions allowed (cannon only)

Both are in character.
Fight is until death.

Round 1 : fight takes place in house of mystery (both have prior knowledge but limited prep,possibly 3 minutes)

Round 2 : fight takes place in England (8 hours prep for John but he is attacked by surprise as Ultron realized he was preparing and decided to attack early)

Round 3 : fight takes place in new york,neutral ground with no prep and is a random encounter.

Final round : If it was to be written in a comic by any famous and well renowned writer,how do you think it would be written and who would win in a small running comic title or one shot film.