So I tried to see if I could break the game, but haven't tested this with a normal deploy with Necrosis. In the attached picture, a Kanen Tracker is Stealthed from Hidden: Vegetation. I was curious to see what error message the game would give me if I tried to use Summon: Skeleton on the tile he occupies (highlighted). It didn't give one, ate my AP, started the Cooldown, and didn't make me a spoopy, scary skelebro (I'm sorry, I had to fit that in, somehow.). Kind of a rare event, because derp. Though I'd assume this isn't exactly WAI, sooo, meh. Remembered I took this screencap, and couldn't find anything like this on the forum.