Intersting... The removal of buff effects is definitely in tune with the theme of
as a purgative force.
Implementation wise, it may be very difficult to restore some effects.
Lobotomize and mutation being the trickiest.
Lobo could be removed by simply reverting the creature to its original skill I suppose so that may be doable.
I don't believe any record is kept of what the creature was before being mutated so mutation is the hardest.
I think that the easiest option for the practical mechanics of the card would be simply that this card acts like a "rewind in place" type effect. So it resets each creature to the state of its base card.
This won't undo mutation, since mutation can leave behind a completely different base card, but it will wipe any stat or skill modifiers that were given. Similarly, it would wipe out both negative and positive stat changes... That certainly fits the "purge" like concept.