Looking at the Shadowlands Maho Techniques, " Commune With Evil ":

Activation : As a downtime activity action, you may make a TN 1 Theology (Void) check.

Effects : If you succeed, you scry for the presence of any Otherworldly or Tainted beings at range 0–6.

: If there are any such beings, they accept your offering, and they augment you with an unholy blessing that increases the value of the ring you used for the check by 1. You can only have one unholy blessing at a time, and it persists until the end of the scene.

+: If you receive an unholy blessing, it temporarily increases the ring’s value by an additional 1 per spent this way.

+: If you receive an unholy blessing, it persists for 1 additional round per spent this way.

Problems with the technique:

1. " increases the value of the ring you used for the check" - but it's a mandated Void check.
2. "it persists until the end of the scene" - since it's a downtime activity, performing it basically is the entirety of a downtime scene.
3. "it persists for 1 additional round" - downtime scenes are not conflict scenes and do not have rounds.