Obi wan was one of the greatest duelists OF HIS TIME. no offense to Obi-wan but Malak could probably beat him. its the simple fact that there is so much lost after thousands of years. just like if a swordsman from today fought a roman legionnaire i think todays would lose. obi wan could use about 3 force powers. jump, push, and probably somethin else. there arent many powers known to any force users in his day. light side guys have push and jump dark side guys have push jump and lightning. and if u watched the yoda and palpatine fight..... dark side push is far superior. sooo im fairly sure that revan would simply pick obi wan up and crush him with the force to save himself the effort of turning on his lightsaber and completely destroying obi wan. i think obi wan could pwn most people in his day aside from dooku and palpatine since he lost to dooku twice and yoda couldnt even beat palpatine.
There is no Palpatine. No Empire. No Jedi. There is no Light. No Dark... Just you, and I, here, now.