How do I remove monsters from the world arena defense?
From your main Island screen ->
Click the battle icon.
Then the arena Icon (NOT the World Arena Icon)
Then the next arena icon
Don’t press but hopefully you will be on a screen that shows “Battle” and “Rival” tabs on the right?
At the bottom of this page it shows a “Defense” Tab.
Click the “defense” Tab
Click the monster you are removing from the Defense (You will need to select at least 1 monster for your defense though).
Click the “Complete” Tab
Hope this helps and good luck!