spells – Is Flame Wisp cumulative with itself?

I cast Flame Wisp, than hit with a Strike. Now I have 2 wisps. What happens if I cast Flame Wisp again?

  1. The new one overrides the old one, I have 3 wisps
  2. The new one is added to the old one, I have 6 wisps (the old one regains, as I just cast a fire spell)
  3. As 2, but every time I hit with a Strike, 2 wisps damages the target

I assume it is option 3, but could argue for 1 as well. Which is it?