Invoke thing...

I have an artifact I'm not sure how to invoke, and I have been trying several invoke words. Anyways, recently I'd invoke my tattoo power in a fight, and then was trying to figure out the artifact again, and as I was trying, I got this echo.. You are unable to call upon the aid of Lord Shokai so soon. I wasn't even using the correct invoke word for Shokai's tattoo (which I do have) Anyways, I was wondering if maybe the tattoo was getting in the way of me trying to invoke the object? I could be way off here, since I'm pretty sure I haven't gotten the correct word to use it, but I may have, but it was trying to access the tattoo instead.