For some reason the calm feture in the Imperials ability dont work sometimes for me, any one else that has this or now why it don't?

Is there a limit on how powerfull the enemy are and if so how do i chnage that?

If there's a limit, I don't think it can be changed. Though, I think each special power per race should work no matter the enemy size, if it's a power that has an effect on other NPC's, that is, like the Nord 'Battle Cry'. It might be a bug, and I don't know if just reloading a save will fix it. You might have to search for an Unofficial Skyrim Patch or Mod.

There is no limit, it will work on any NPC, but not creatures.

OK then it must be some bug, tested with a new game start and it's still bugged.

?? really?

It worked on a frost troll a year ago.

edit: Ok, according to the wiki it only works on NPCs http://www.uesp.net/wiki/Skyrim:Voice_of_the_Emperor

But it really worked on a frost troll that time. Unless trolls are NPCs.

Shhhhh!!! Don't hurt its feelings!

OK i know what the problem was now i hope, i have changed it so that calmed enemy's will fight with you under the spell duration...but if you use the vanilla "MagicCharmFaction" for CharmFaction in the Papyrus it will not work all the time so i changed it to "MagicAllegiamceFaction"...seems like that did the trick.

Alright, I shall assume you're using the console. That would probably do it.

No PC and CK

Sorry, what I meant was the PC Console/Mods, but yeah.