Can you use the evade action vs "shrouded" creatures? If so how since you can't look the side of the card with its statistics.
1 Answer
From the rules reference
You can perform the evade action only if you are engaged with one or more monsters.
And from Secrets of the Order Expansion Rules the example given says
During the monster phase, the Raging Poltergeist moves into Agatha’s space and engages her (2). The monster card flips to the engaged side and becomes a Confounding Specter, revealing that its health is two.
You can't use evade without being engaged to a creature, but once they are engaged you reveal the side of the card with the statistics. Once an investigator is engaged to a creature, they can use the evade action.