Well Xavier destroyed Magneto's mind in the Fatal Attactinons saga, but he didn't really have much chance to fight back. It really depends on how fast one can take out the other. I don't know, lol. I'm just rambling.
this ones hard, but i think i'll go with magneto for now, i dont know about him having mental barriers (although it would explain that New Xmen story arc) but his attacks (energy wise) are really strong, and of course theres the power to manipulate metal (although i dont think he'd need it)
I'm not sure about his "resistence to psionics", Xavier has always been able to give magneto painfull thoughts about losing his family and etc....that was his successful plan of attack. of course mags can control his wheelchair which is why Xavier walks in this match up, i think Xavier should be able to slow mags down enough to where he could hide at a safe spot while ruthlessly tearing up mag's mind.
And you cant rely on marvel.com man, just read some of their bios...its mostly incorrect.
magneto doens´t always uses a mental barrier, and you can go whatever site you want, you can ask stan lee if you wish, he has that habilitie. xavier is good but mags is better, after all our discussion about mags fighting other guys, do you really think he needs to use the wheelchair to attack him.
i´m not saying a good telepath wouldn´t eventualy break trough his menatl barrier, but it would take some time, and in this minutes or seconds, mags takes him out.
They both attack at the same time. Xavier attacks the mind, Magneto attacks the body. Magneto has some psionic defences that Xavier has to get through before he can hurt Eric. Xavier has no such defences against Magneto's attacks. Mags wins.