Episode 31 of The Trigan Empire
The Miniature Killers of Zelph
aka The Black Duke
De zwarte hertog (Dutch title)
The Black Duke (Dutch title, translated)
Written by Mike Butterworth
Illustrated by Don Lawrence
The Miniature Killers of Zelph was originally published in 8 installments in issues 527 (19 February 1972) to 534 (8 April 1972) of Look and Learn magazine.
It is reprinted in the Don Lawrence Collection Volume 8, The Prisoner of Zerss.
Installments
527 528 529 530 531 532 533 534
Links
https://www.slideshare.net/luisnarbona/02-the-minature-killers-of-zelph-10048239
531
https://www.catawiki.com/en/l/1447495-44-657-don-lawrence-trigan-empire-original-page-gouache-on-board-de-zwarte-hertog-the-miniature-killers-of-zelph-1972
Plot summary (Dutch)
Downloads
MediaFire via British Comics Compilations
Is Zel the same stuff as Trigonium?
I would say probably not. Trigonium is probably the same stuff as dorana, after which the lost city of Dorana is named.