Not tentacles, octopi, old gods or void lords. Just, you know, SHADOW
If you mean the original “class fantasy” of shadow priest and the visuals that moved to void over the years.
I’m not a shadow priest (Holy forever!) and I don’t really pay attention to the spec, but the impression I got over the years is mostly because lore was expanded, class fantasy diversification was required and just being “practical” with assets.
Shadow magic was not as detailled of a concept when WoW launched compared to now. Shadow Magic wasn’t all that voidy, because the lore just didn’t expand on shadow magic that far until many expansions later. I don’t think anybody at Blizzard knew that they were creating concepts that would have to last 20+ years. It was the anti-Light magic. The Cosmic forces graphic that came from World of Warcraft: Chronicle Volume 1 was still far away. Shadow was just bad magic. We were coming from Warcraft 3 where shadow magic was mostly tied to death and demons (Scourge, Necromancers, Burning Legion, Demons, etc) but Blizzard knew they wanted to do Death Knight/Necromancer eventually so they stayed off the death concept for shadow priest and warlocks. It was more on the “psychic” side. If Holy could cure the mind, Shadow would harm it, which is why we have spell named: Mind Blast, Mind Flay, Mind Control. And there was even alpha spell like Mind Rot, Shadow Word: Fumble or Sleep. Shadow Priest came from the the duality of Holy versus Shadow, not from tentacles.
That concept lasted until Wrath/Cataclysm. There was sometimes discussion about warlock/shadow priest and how close they could feel. Even if warlocks were mostly on the demonic shadow side with curses. They were into the same lane of shadow magic, and it was sometimes difficult to make them “unique” how they used shadow. As specs were expanded, since shadow priests were into the same lane as Warlocks and Death Knights (introduced in Wrath), it became natural for Shadow Priest to move on the Voidy side that became more present over the years. But it wasn’t without experimentation. I still remember how they toyed with the “raven” visuals for a while, but they were embracing the void concept slowly (Voidbender, void tendrils), The visuals were already introduced after Cataclysm, Void (not just Old Gods) became a major player in the lore, just like Warlock was to the Burning Legion, Shadow Priest would be with the Void, they just needed a class rework to bring it fully in. And it fully became void priest in Legion, when another shadow magic user came, Demon Hunter. Warlocks will remember giving up metamorphosis to DH too, the shadow magic lane sure is crowded! (while Holy Priest and Disc priest twins are fighting over the same Holy toys and Paladins are pushing crayons up their noses.)
When they expanded the Old God themes, that brought in more expanded lore on the void. All the cultists from Cataclysm were coming with more void aligned spells compared to Twilight Hammer NPC in Vanilla WoW, it was just practical to reposition shadow priest away from the simplified concept of “shadow”. And more practical, because there was a whole new visual created for void magic that could pulled into them that nobody else could use each time they introduced a new class. Shadow priest is the only class spec that can really use well that class fantasy with tentacles.
In a way, the psychic theme of shadow priest is still there and was closely linked to Old Gods/Void magic from the start. I still remember that Night Elf Priestess, Natalia Mar’alith, in Silithus that turned mad questline during vanilla WoW. The lore reason would be that as shadow priests learned to face the void and Old Gods, Shadow Priest learned to embrace the more void appearance of their shadow magic just like the cultists they faced.
I think it’s more that shadows class fantasy prior to legion was it’s absence of clear fantasy, at best we had a vague idea of what shadow magic was and ultimately were left to make it up for ourselves.
Well you see shadows need light to cast them and the electric bill was too expensive.
Personally I like the direction into the void, but not at the cost of being a Mindflayer. The idea that I have the signature abilities of a DnD Mindflayer and its expanded with Voidform rather than a true ceremorphosis is quite interesting. I also think they should build off that with confusion, sleep, and better Mind Control.
I really wish they would dial up the Mindflayer abilities and simplify the design with that theme in mind and the utilization of the void being a product of a Mindflayers power.
I mean, I like void magic (especially for Void Elves) but selfishly speaking, I don’t like for my Forsaken spriest, because it completely nuked the fantasy I had from an OG undead priest. It just feels wrong to use the void side with him.
It’s more about a writing direction thing, but I think they could’ve developed Void magic in their lore without exactly dampening the previous Shadow. Best case scenario would be adding a fourth dps spec to priests or a completely new caster class.