LOL you all have interesting ideas. for me i am undecided.
superman needs our sun to have his powers, so with out it he would be average.
That materia could be similar to kryptonite, but if they are a different metal they could strengthen superman
Seph is very strong and fast, but a sword doesnt fight well against a man who cant be cut, shot, etc
last i remember about both characters, they both die and happen to come back later on, so it would be an almost ancient battle. depends on who can go the longest and who is older. The older, the sooner you die.
seph doesnt need to get close, he can cast magic, and superman can use lazer eye beams so there is no *play dead* tactic
heroes dont always win! there is no such thing as plot device in this case.
If i had to put money i would put it on superman. there is alot of what ifs, but with out those seph has no weapon against superman. he can move and dodge and hit, etc, but nothing solid to take superman down. where as seph isnt indistructable like the man of steel
*FU if you think i misspelled alot. its 2:05 am.