Is cleanse pattern lasting, otherwise what does extra potency provide?

Question

Cleanse Pattern is on page 168 of the new edition of Mage the Awakening and says:

With this spell, a mage removes the tell-tale signs of Awakened interference.

But it's primary spell factor is potency which had no mention in the rest is the spell's text.

It would seem useless to only last a turn (which I think is the unaltered duration), instead of being lasting. A lasting spell wouldn't need to have a duration spell factor. Thus my assumption.

So which is it: lasting or using duration as the primary spell factor?

Answer 1

[Disclaimer] I don't have the new version of Mage.

Generally if a spell does not have a listed effect for Potency (especially for Duration spells), then Potency will determine the difficulty of dispelling the effect early or otherwise overcoming the effect through other means (where applicable).

In this case specifically, I would say that the Cleanse Pattern spell is like splashing paint remover on a painting. It's meant to cleanse the lingering signs of magic away. The higher the Potency, the better the Mage is at returning the 'painting' (spell target) to a 'blank canvas' (target never affected by a spell).

Thus, the duration is Lasting and the Potency of the effect would be used as a Threshold for those attempting to detect magic use on the target. Beating the threshold would likely even reveal not only the initial magic use, but also the attempt to obscure it!