Borbarad
Advocatus Diaboli
Hmm...I have to say I don't really know who's going to win here.
Revan:
- prodigy in lightsaber combat and force use (as it seems - possibly using a unique style)
- 3 years of war experience (Mandalorian Wars)
- defeated pretty nasty opponents (Yusanis, Mandalore, Malak)
- eventually gathered tons of knowledge about the force (Jedi, Malachor V, Korriban)
Kyle:
- gone through Imperial training and became mercenary / spy (argueably the best mercenary in the Galaxy since he was able to best Boba Fett as well as Dark Troopers in shoot-outs)
- 4 years of Battle experience (Galactic Civil War)
- also prodigy in lightsaber combat and force use (proven by the fact that he defeated 7 Dark Jedi in lightsaber and force combat - when Jerec was a fully trained PT Jedi Knight / Master partly powered up by the Valley of the Jedi - without actual training)
- fell to the Dark Side and was redeemed (MotS)
- defeated Desann and a variety of Dark Jedi in JK 2 (possibly got a nice boost in power by stepping into the Valley of the Jedi's core beam)
- became Council Member of the NJO as well as the foremost battle master (training people like Jaden Korr).
- if we count the Dark Side Ending of JA in he was able to force push a Jedi through an entire room and survive a blast of Ragnos sceptre which we have seen tearing down walls before
- also possibly using a unique style or several blends of styles
- another 5 years of war experience added through the war against the YV.
I don't know who's more powerful here but Kyle has by far more experience compared to Revan (combat experience, war experience, force training, lightsaber training and use of both force and lightsaber) although Revan has an advantage in knowledge (although I have to say that Kyle had access to knowledge that was stored on Ossus, pretty much all of the PT era knowledge and some knowledge from the pre-Ruusan era).
I think this would be a pretty tough fight. Revan might manage to come out alive (if he pulls some uber Sith powers out of his sleeves) but unless we get more knowledge about Revan, Kyle might also be able to win this. I really don't know.