Step 1) cryo prison
Step 2) While they are in stasis, we develop mind prison technology, a virtual reality prison that uses a new developed technology allowing us to map their brains and upload their consciousness
Step 3) miniaturize mind prison, equip with an infinity drive, something something plutonium encased in 3" thick vibranium. Upload them into the mini mindprison, launch into deep space, the battery lasts 10,000 yrs, upon tampering it plays a recorded message explaining its purpose, then it wipes the memory, filling with random data 8 x 10^1024 times. Unless tampered, they cannot reincarnate for 10,000 yrs. Add solar power and extend this to 10B yrs
Step 4) call this mini mind prison virtual reality "the Phantom Zone" -- this is mandatory!