[Yvelina]

Purgatory does hurt your own undead.

In my opinion, it is rather useless. It is a Thaumaturgy level seven spell, and it mostly affect wimpy undead that should not be an issue by the time you can get Purgatory up.

Look at it this way. Either you are a fire nation, you already have Evocation seven, and can use Fire Storm to get rid of the weak undead while you kill the SCs, or you are not a fire nation, and by the time you can afford to cast Purgatory, a global slot should never be wasted for such a relatively inneffective spell.

In a few, very specific cases, it may come in handy, but it would be a far-fetched scenario... and of course, the Powers that Be may be listenning, and I may have to do exactly that in 'Live and Learn'.