Sacred Haven of Debauchery

I had about fifteen skeletons and a hero. I tried to turn the hero, catapults, and a couple of mages on the other side of the base into skeletons, but it didn't work, and the hero was killed. I turned the fifteen skeletons into white skeletons, and then they were all killed. And then, after ten seconds, SUDDENLY, several dozen liches appeared in their place, so many that they didn't even fit into one unit. I used them to repel huge hordes, destroyed a titan, and then cleared half of the base until they were killed. Also, their ability to raise skeletons didn't work; it just flashed lightning and did nothing.