Moon Knight was a show that dared to be different from the Marvel Cinematic Universe in a variety of ways. Not the least of which was how the show didn’t have any “at large” MCU connections (they were considered, however), and of course, how they dealt with mental health and how the protagonist of Marc Spector went and dealt with his childhood trauma by creating the split personality of Steven Grant. But the use of villain Arthur Harrow was also well handled in the eyes of many fans.
This was a cult leader who was trying to make a “better world” with the help of the Egyptian Sun God. But while that in and of itself is a kind of trope, he honestly wanted to make lives better, and was more than willing to sacrifice himself to his god when he found out his own scales weren’t balanced. He had 100% devotion to the cause and wanted the world to be safe from harm.
Naturally, Moon Knight didn’t allow the plans of him and his god to happen, and actually combined the two so that they would be powerless within one another. But that’s not how it ended. Rather, it ended with Khonshu (Arthur Harrow’s former master) showing up to get Harrow and then having Marc’s OTHER split personality in Jake Lochley shoot Harrow four times before driving away in his limo.
Usually, that would be the end of things. Except, in an interview, Ethan Hawke (who played Harrow) teased this:
“Sure doesn’t seem dead to me.”
Now, that could mean a myriad of things. Plus, we don’t have word if Moon Knight will get a second season. There’s also the possibility that Harrow returns in ways beyond the main plot. As his backstory isn’t as fleshed out as Marc Spector’s.