The wiki says that it allows you to control stuff. Does that mean that I can finally get a horker follower?

It allows you to control a lot of things. When you have every word, you can control dragons, people, etc etc. For some reason it doesn't work on Draugr though (in my experience).

It says level 2 works on mortal enemies so I guess undead don't count since they are dead even though they could still be called mortal since they can die again if you kill them lol. level 1 is animals and 3 lets you tame a dragon to semi fly around on and travel with.

Yeah, lol. Semi fly around was pretty accurate of a description.

call me crazy but i think it lets you bend someones "will" whatever that is