When I first found the stone and activated it, then used the power it reanimated the nearest dead "creatures" a skeleton and a wolf. The Necromancer did not rise, so I figured maybe it was because I looted her corpse.

So, I killed off the skele and wolf, waited a day and used the power again.....nope still wouldnt rise. So I gave up on the mancer and went on my merry way. I have tried it on many other creatures and humans but still nothing happens.

Their corpses just twitch a lil bit but thats it.

Any suggestions?

Don't use it then

How do I activate this power at all? When I enable it in my inventory it doesn't go into either hand. It shows that it's enabled similar to armor. So how do I activate it in battle?

Powers activate using the Shout key, default Z on PC.

Ah, thanks!