Randal the Vandal is the final boss in Prison of Elders. He will ride in on a Wolves Walker and call forth giant shanks that have shields that can only be penetrated by No Land Beyond. The Walker has extra armor on the legs that can only be removed by a thrall explosion. Once the brain pops you have to set it on fire to do any damage. Then once it's dead Randal dismounts and calls forth an army of captains for support while he peppers you with an endless barrage of line rifle shots and shock pistol rounds. When his health gets down to half he enrages and calls endless waves of stealth vandals. And now has a shield that can only be taken out with rotating void solar or arc damage and once that's down he can be killed with that big rocket launcher thing. Your reward is: 5 glimmer.