This battle brings up the legendary question, “Can Fire beat Water?”. I’m inclined to say yes, but it can be difficult in most cases. Tahu’s flames wouldn’t be able to burn away Vezok’s water, (Through evaporation) but he does have his swords at the ready. Vezok has quite a few projectiles, including his Water Harpoons. I believe that Tahu will be able to parry them with his swords and then deal a finishing strike against Vezok. With his lethal swords, one good hit is all that Tahu will need. Getting that hit is the main problem, but I believe that he will pull through. If not, Tahu does have his merged form. Tahu wins.