Whoa, you use Luffy/Renji too? …Weird... I use Afro Luffy's laughter Koma though. I haven't played online yet, but the guy I usually play against has a fair amount of trouble against this deck. I usually use Allen/Sanji though. The only thing he really has that can beat this is Gear 3 Luffy deck with help Koma out the ass.
I used to use Allen. I still do from time to time, but I just don't find him to be that great without a shitload of help Koma's. He's great as a leader (In a solo deck), but he doesn't fit the "back up" character I need for Luffy. He just can't take the damage, and I always feel like I'm on the run.
As for Sanji, I honestly wont use him because A) His Guard Break takes like… 5 seconds... and B) His head is too big.