powered by the apocalypse – How does the Nova Burn Power level 7-9?

In Masks, The novas have the power of burning:

Burn

When you load your powers, get + the conditions you have currently marked. On one stroke, hold 3 burn. On a 7-9, mark a condition. In case of absence, hold 2 burns and mark three conditions.

Pass your burn on your flares. You lose all burns at the end of the scene.

Choose four flares.

It is a power that owns Novas, a basic class. They can get this resource and use it to do fun things, like picking up buildings,

How does this power on the 7-9 segment work? Do you also hold 2 burns? Do you hold 3 burns, since if it's a blow you're holding 3? Do not you have a burn for segment 7-9? I really do not know what is the experience envisaged for Novas.