Crushing his skull isn't enough. Make him suffer.

MODS; MALFORM HIS BODY INTO AN AMORPHUS BLOB THAT IS IN A CONSTANT STATE OF PAIN, DOOMED TO LIVE UNTIL THE HEAT DEATH OF THE UNIVERSE, HAS SUCH WARPED PERCEPTION OF TIME THAT SECONDS FEEL LIKE YEARS, UNABLE TO HARM ITSELF AND HAS NO MOUTH TO SCREAM WITH