When those magi chapters where it was revealed that Aladdin, Alibaba, Hakuryuu, and Judar would be going through all of Sinbad's dungeons were released I wrote a post about how I hoped Alibaba would be the one confronting Zepar's dungeon, considering the subplot of Sinbad using that djinn to control Kougyoku. Either him or Judar, because Zepar was Serendine's djinn. But nope, ohtaka chose Aladdin of all people.
Now that post was before the zepar chapter was released so now that the manga is over I still stand by Alibaba being the one that should have stayed fighting Zepar and Aladdin going further. Heck, I wanted Kougyoku to have closure with that, it gets better when you know that in that battle there were two zepars (Sinbad and Serendine) so having a 2 vs 2 with Alibaba/Kougyoku vs Sinbad/Serendine would have been amazing.
Why Alibaba and Kougyoku? besides the Zepar subplot in second balbadd arc these 2 are the one who used to idolized/love Sinbad that many times were blinded by his greatness. Now the two team up to make the Kou company, Sinbad's company biggest rival. Basically the Kou empire and these 2 kids managed to surpass him.