I am going to reply in English here, even though Greek could be a valid option as I see. :-)
All vetiver accords I have made for fun or exercise always benefited from the addition of black pepper EO.
Now, I am no big fan of black pepper EO as I feel it smells kind of boring and "depressed" but with vetiver it always worked well during the first couple hours or so..
I know I have more to offer on this subject but at the moment black pepper is the only thing I can think to suggest.