He's a lucky charm, ain't he??!
Note: Minify the command to avoid issues :)
Tried At The Furnace, Armor Stand Generation!
Dust Devil Minions!
The Possessed Blade!
Steed 4: Evil Steed!
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)