How do you beat the final boss in dragon quest monsters joker

I recommend you have at least one s or x rank and a demon-at-arms, because a s or x rank is strong once you raise it enough, and it is easy to raise, and a demon-at-arms can attack twice and one thing about him, his team can attack five times.
Freelancer65:
You can use a team that consists of
Atlas (lv 45 - 50)
Drakulard (needs good defence and make sure it has kabuff)
Zoma (zapple or kazapple and desruption wave )
use desruption wave to get rid of all barrier attacks that the wight king uses