For Me, after the first one. the second was invisible after I left the base and came back, the third one did the same. the first one I made has not just disappeared its no longer listed as one of my thralls. the second one that was invisible is now visible. How am I going to have a undead army if I cant se them and they keep dropping outa the game. Now the berserker I made into a zombie is invisible too. 4 made, but only 3 present. How many will I have tomorrow?