I'm having a similar problem/entertainment with my current legendary prisoner. He also has a luxury cell and frequently smashes up his cell and then goes on a killing spree when the guards try and restrain him. He's 21 and currently serving 610 years in SuperMax for murder and torture.
Not only does he have his own cell but he also has his own cell block. Complete with 19 other cells (in case he gets any future neighbours), yard, canteen, kitchen and solitary cell (in frequent use). 2 armed guards, 3 guards and a perimeter dog patrol. His needs are quite low but he's extremely volatile and an alcoholic.
Losing the no incidents daily bonus is annoying so to try and rectify this I have tried punishing him which doesn't work because - like you said - he just kicks off as soon as solitary has finished. To make it worse, my prisoner is stoical so he doesn't get suppressed. You could consider permanent solitary confinement but I don't think that's an option for death row inmates as they are, of course, on permanent lockdown. I may be wrong.
Option 2 was reform. My prisoner is an alcoholic and I have (somehow) managed to get him onto the reform programme. The issue now is that he doesn't attend so he isn't going to pass it. However, I have noticed that he doesn't crave alcohol as much even for just being enrolled on the course... He seems to be skipping the programme because of the punishments being dished out so you could always alter these on the relevant screen to make sure that a prisoner attends a programme.
If anyone has any suggestions as to how to get a troublesome prisoner to attend programmes to keep there needs down then please say!
I am currently going for a third option which is simply containment. Keep the prisoner isolated so that they don't interfere with the rest of your prison. You'll have a lot of property damage and a few deaths to staff (especially when they steal a shotgun from armed guards) but this can be nipped in the bud quickly with enough guards nearby no matter how 'legendary' they think they are.
That seems to be working for me. Punishment, reform and containment. If you aren't enjoying the prisoner rioting constantly then the fourth option is to eliminate him. Put freefire on when things escalate. Final option is to, as suggested, lock the cell door (or two so they don't escape) and stave them to death.
Personally, I get a fair bit of entertainment value from having the maniac prisoner in my prison and I do generally want to help him to behave but sometimes the only way is out (in a body bag).