Heres a tip FOR ALL THE PEOPLE SAYING YOU CAN FORCETAME IT IN THE ARENA- if u go into the bosses arena and forcetame it.... you'll be stuck there forever bc the boss gotta die in order for u to leave. :)
To kill it use a sniper and shoot the opening in the center of the diamond shape thing then that’s how you damage it. If you attack the outside it does nothing it just damages you I hope you follow that tip. Trust me.
for ps4 players open the pause menu click r1 l1 square circle triangle all together and the screen will close then reopen it and a bar will appear write to us admincheat forcetame aiming for the boos and you will have tame the boss