This is not a boss battle just a hard zombie
Note: Minify the command to avoid issues :)
Powerful Skeleton Riding Powerful Zombie
Crusher[BOSS]
Sam/Jacksepticeye Boots!
GOD SWORD!
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)