....
Is there no one that will take into consideration the strength of the individuals strengths? -.-" for a debate, your basing what you know and taking everything into consdieration, regardless of his loss. Its techniquely a draw, 1-1 on each side if you've payed attention is what im saying.
Riku KH/KH2
-Wisdom, from past mistakes
-Lingering darkness that manifest into Ansem and the Guardian
-Original kingdom keyblade master and later way of the dawn keyblade master
-The use of said darkness
-Transdimensional travel (between worlds)
-Long arm blade style combat (when his arm reaches back with souleater and wotd)
-Eternal Session Limit (with sora...badass)
Roxas:
-Dual weilding prodigy
-Unique nobody based attacks
-transdimensional travel (between worlds)
-Decent speed, flowing body movement
-Keen instinct
-Alot more aggressive (Riku is calm no matter what, in KH2 anyway)
-Sora's nobody (can only live up to half of the true form's power)
Statistics:
Power: Riku > Roxas
Speed: Riku = Roxas
Intelligence: Riku > Roxas
Potential: Riku < Roxas
Experience: Riku > Roxas
Better chance against Sora: Riku < Roxas (simply for not fighting with restraints)
More developed character: Riku > Roxas
This is going by what we know and its entirety, Riku seems to fit the bill where Roxas can't. Anything else to add would be really helpful.