Geez guys, Don't you get it? He is not Riku's nobody nor a keyblade master. And doesn't have any fricking weapon if you don't includin the ****ing mind! , He's using Riku's mind to fool him . And if he could've met Sora he would have used the keyblade and if he wanted to fight Vexen he would have used the shield.
Nothing than that... Sheeesh is it so hard to believe? Zexion perhaps looks cool but he's the weakest from them all, sorry
Really ? Because if your reasoning was true then why do Vexen and Saix have weapons? Pi