Festergut quickie: use Shadow Ward

I hadn't seen it before, until I searched specifically for it. Festergut's gaseous attacks are not poison, like I had thought, but actually shadow damage. This means that you can avoid a lot of damage, especially at the start of the fight, by maintaining a Shadow Ward on you. It could make sense to even roll it into your spell rotation as it's cooldown coincides with it's length, 30seconds.

This trick is mentioned in the Flu Shortage achievement comments.