BlazBlue Entropy Effect Dead Cells crossover DLC how to unlock The Prisoner and solve the riddle

How to solve the underground riddle? How to unlock The Prisoner for free? What's the best build to win the Titan sentry boss fight in unlock event? 0:00:00 how to find the Dead Cells event 0:02:39 how to escape the worm 0:04:19 how to open wurm's head 0:04:50 walk on walls upgrade 0:05:35 riddle hints 0:06:35 how to solve the eyes riddle 0:07:35 unlocking skills and extra skins 0:17:30 how to win against the double boss fight