It was such a weird casting choice. I never saw Reign but it was mentioned several times here so I decided to investigate. It appears that he was cast in TLK almost right after his stint on Reign ended and had a pretty decent following from that show, so very strange that they put him in such an unappealing/repulsive role that's also very much in the background. I'm not advocating for typecasting, and he was very convincing as a bad guy despite underwritten role, but that was not going to bring in his followers to a show that BBC anbd later Netflix didn't bother to promote. So every following counts. Like, if his character had a Jaimie Lannister type of arc than yes. But this role was really a big waste. Imagine if you cast Alex Dreymon on the heels of TLK and put him in the most unpopular role you can find - repulsive villain who doesn't even get to do much action and who is basically a background player that everyone throws insults at. That's what happened here lel.