When reading his class cards, something came into my mind.

Tempest includes this line: "... If you fail, recover 1 (fatigue)..."

Ancestors spirits has this: "... When a hero recovers (health) or (fatigue) due to 1 of your class skills..."

Do these two interact? Nothing actually very important, useful, or game-breaking, but just noticed that possible interaction.

Yep, Ancestor Spirits can be used in such a situation. Even though the recovery occurs because Tempest failed, the Spiritspeaker still is recovering fatigue due to one of their class skills.

Throw the poor class a bone.. it needs all the help it can get!

Also don't forget the errata for Ancestor Spirits. It is supposed to affect every hero OR every monster that was hit by the class skill (e.g. in the event Tempest actually works, it can do a lot of good)

Thanks