Overview
After losing 3 gaurds and 1 armed gaurd to a 「Legendary Prisoner」, my quest to neutralize him began. After a dozen more gaurds and hours (15 minutes) I came to a conclusion: Killing the 「Legendary Prisoner」.
How to do it
First and foremost, you will need to unlock 「Permanent Punishments」, 「Gaurd Patrols」, and 「Armed Gaurds」 through bureaucracy. Once done, get rid of normal gaurds stationed and patrolling solitary confindment. Send the 「Legendary Prisoner」 to solitary ( not permanently) and deploy 5 armed gaurds right in front of his cell (use armed patrols to do this). Turn on freefire and change his punishment to 「Solitary (Permanent)」 and lastly, wait for him to destroy something. The armed gaurds should then rush into the cell and feed him lead at point blank.