[thejeff]

Yes, it's the penalty of being mindless. I've never quite seen how a mindless thing can cast spells and act on its own, anyway.

They dissolve randomly, just like any mindless unit. If you watch longdead disappear after the last commander flees or die, they don't go all at once.

What I didn't expect is that the Blood Fountain stopped acted when Mictlan routed. Immobile, so it couldn't flee, but it didn't keep casting either. Maybe I've never seen an immobile in that situation before.