The purple particle cloud and purple trail that appear upon cast are currently bound to Jex circling around Dark Willow. This means whenever you lose vision over Jex, the and trail disappear, even when having vision over Dark Willow. Upon gaining vision over Jex again, the effects appear again, but kinda spasm and go all over the place.

The purple cloud and purple trail should be bound to Dark Willow, since they follow her and not Jex. Only the pink effects and sparkles around Jex should be bound to Jex, since they follow Jex.