When facing a Rubick, who steals Ice Vortex and casts it so that it overlaps with Anient Apparition's Ice Vortex, neither Rubick nor Ancient Apparition are affected by the positive and negative effect at the same time when standing within the overlapping area.

Repro:
1. Cast Ice Vortex
2. Have an enemy cast Ice Vortex on top of your vortex
3. Stand within the area of both vortexes

Result: You either get slowed and have your magic resistance reduced, or you get your movement speed increased. You are not affected by both at the same time, despite being within the area of both.

Expected: The positive effect and negative effect should both be applied when within the area of both of them. The buff should use a separate modifier than the debuff.