Would be interesting to have at least one DoT to maintain while going through the priority rotation. Maybe it could be tied to Verstone/fire procs.

Verpoison (terrible name) | Spell | 2s cast | 2.5s recast

Deals unaspected damage with a potency of 80
Additional Effect: Unaspected damage over time
Potency: 30
Duration: 27s
Verfire Ready Additional Effect: Increases Black Mana by 6
Verstone Ready Additional Effect: Increases White Mana by 6
Can only be executed while Verfire Ready or Verstone Ready is active

It requires a "Ver-spell Ready" proc to cast and grants mana for the proc consumed. If both procs are active, then it consumes both and grants mana for both.