[Viperianw]

hey guys, i know a lot of people have been asking this question, and i was curious about it as well since i haven't been on in a while. i did some digging, and it turns out that the way you get it is by beating the water arena leader (enter arena through ocean breeze city)

then you can equip it onto whatever monster and access the npc in the fire arena that's separated by the lava lake  hope it helps

edit: the fire arena event NPC doesn't drop anything for me right now, so maybe don't challenge it yet!

[S_avageGaming]

You only have a certain chance of getting the drops from the event NPC. It drops Wise Warrior and Gale Force Boots. 
When equipped, Wise Warrior increases the damage dealt by the holder by 10% each turn. It caps up to 60%. Gale Force Boots increases the holder's Speed by 25% and the Critical strike damage by 30%. 
         Hope this helps! 

[Viperianw]

indeed, that's good stuff to know :D for me, though, it keeps making me battle it when i am there, and there is no way to escape it–it doesn't return the normal prompt when i beat it