Episode 71 of The Trigan Empire
aka De tirannie van Orismo (Dutch title)
The Tyranny of Orismo (Dutch title, translated)
Written by Ken Roscoe
Illustrated by Gerry Wood
The Killer was originally published in 4 instalments in issues 840 (18 February 1978) to 843 (11 March 1978) of Look and Learn magazine.
To date it has not been reprinted in English.
Plot summary (Dutch)
MediaFire via British Comics Compilations