When he first met Magus, Spekkio made a comment somewhere along the lines of this guy could probably teach me a thing or two! Well, over the past couple of years, Maguss power has increased exponentially. The poor little God of War never stood a chance.
I was right!
No living thing can kill Spekio.
magicians and sorcerers have supernatural powers, and those things can totally kill gods and stuff
That explains EVERYTHING! :D At least about why Crono and the girls can't use magic...