Lingering is an exclusive metablast does no immediate damage. Instead, you set up a patch with a diameter equal to your Magic in meters, that will damage anyone spending time in it. Anyone inside this area suffers damage for each action they take inside the patch. Movement does not count, so it is possible to rush through or out of it without taking damage.
Ignore to-hit rolls and just make a roll and add the result (positive or negative) to the damage rating.
The patch is clearly noticeable, but transparent, and lasts until the end of the Sequence unless you spend a Magic point, in which case it lasts until dispersed (at least a few minutes).
An exclusive metablast has none of the normal effects of that blast, including any other metablasts that would ordinarily apply. In effect, an exclusive metablast is a separate effect that replaces what the blast normally does. Still, it takes it's appearance from the blast it is used with, if it does any damage it is of the same type, and a Damage Imunity that would protect against the blast also protects against the exclusive metablast.
If you must always use this, and thus cannot use the blast power to do direct damage, the metablast schtick is free.