I loved the whole bloody unholy frenzy animation from WoTLK, really fit thematically with DKs.
I would love a glyph to change the way my ghoul looks during dark transformation. In Legion when you had the abomination pet, you got the festergut and rotface models for your pet during dark transformation. They looked so much better than the goofy, normal dark transformation appearance.
Would love to have presences back, swapping between them felt meaty and they had nice graphics.
I actually love anti magic shell’s graphic, if they changed it at all I would want a glyph to preserve the current one.
Death and Decay should look more pronounced. One thing I liked about the old spell animation is how strong the glow effect was on the ground.