In our regular Shadowmoon time line, the orcs dabbled with the “Dark Star”. After seeing what it did to the shaman who looked too deeply they forbid ever touching it again. It was labeled as evil, and strictly forbidden at the risk of exile. Then they went back to only focusing on the stars and the elements.
The AU Shadowmoon would have had the same story, but rather than Ner’zhul giving into Kil’jaeden pretending to be his mate (because she was still alive in this time line), he instead fell into desperation to save his clan and broke their law of not tampering too far into darkness of the void.
This caused the AU orcs to split. Rulkan became Chieftain basically and the Shadowmoon Exiles held onto the tradition of never delving into the shadows again.
Every Shadow Priest/Priestess in WoD was a hostile enemy mob.
Now, if you’re using the term differently in reference to Shadowmoon clan more inline with the darkness of night and moon…maybe. But they would be misrepresenting themselves I feel.
Now, is it totally out of the realm of possibilites that an AU Mag’har could be attempting to try and be an shaman and deal with the shadow and balance something that was forbidden?
Not at all.
But it must be approached with the full acknowledgment that this was against their own clans beliefs and law for good reason. The shaman who looked too deep into the void began abusing and desecrating their own spirits and ancestors, who are the most important aspect too shamanism. So if you approach this narrative with the understanding they are doing something controversial and could possibly have them seen as going against their own clan, then fully possible (no matter what other character may say to you that makes it seem okay. Some people don’t know the full weight of these choices and may just hand wave it IC. Keep to your story, let it keep its weight. The importance of your story telling be seen and effect other players)
A Shadowmoon shaman will most likely be a “priest” or mystic of his clans beliefs. In reverence to the moon, the understanding of the stars and their conversation with the ancestors. There will also be a leaning to enjoy the night time more for these reasons hence the name…Shadowmoon. Since they always lived in the shadow of the moon.
You could always go the route of an orc attempting to reconnect to their shamanic roots after being forcibly converted to the Light or accepting the light thinking they use Shadow in a desperate attempt to connect to the night. But it won’t end up being what they want. The shadow in terms of light rely a lot on fear, instinct, chaos and darkness and often drive people to mindness if not understood.
So there is always a potential to try and approach anything you want, but I think even on the Iron Horde, nothing of what they were doing were good and would not be the shaman they once were. They might even be dark shaman at that point, which would be even more of a no-no.