A bit of background. There are four magi trapped in a rego, these being the magi who were participating in a Wizards Communion that was Opening an Intangible Tunnel whose parma was not high enough to resist the magic grabbing them. Two of them are player characters, two of them are one shot magi which I created so everyone would have someone to play.
They were attacked by a group of wolf skinchangers. Three of the four magi were wounded, two of them very badly. One of the badly wounded ones was the Creo Corpus Tremere magi which I had specifically added to the group to provide healing. At the end of the fight he had three heavy wounds and an incapacitating wound. Through some good luck, the incapacitating wound eased to a heavy for a total -20 penalty. There is the Bjorner PC, who took 3 medium wounds and then three light wounds for a total penalty of -12. Then there is the Flambeau whose good armor meant he only took 3 light wounds. Finally, the Meritia created a glamour of a dome of diamond that covered her, and emerged unscathed.
Now, as I read the rules, you can't cast magic that requires fatigue if you have any wound penalty. But the Flambeau has a touch range, sun duration version of Endurance of the Beserker. With his casting total, the aura modifier and the wound penalty, whether casting this spell costs fatigue is iffy. If it does cost fatigue, what happens? Does one of the light wounds become medium? Does the spell fail and the light wound became medium? Do I say, "No, can't do that right now, try again later?"
Now, supposing the Endurance of the Beserker effect goes off. No one has Churgery, or the spell Bind Wounds. The Flambeau could spont Bind Wounds fairly easly, but as something that causes a fatigue level, does this cause one of his wounds to worsen? Or does the effect of the spell keep the wound from worsening?