Help Me To Find an 90's Alein Movie?

I Remember Wathcing it on my VHS in 90's kind of sci fi action flick storyline is little similar to men in black (Aleins In Men Skin) & all i remembar was that main antagonist of the movie is n alein too with some powers & whenever he shouts "Griever" he turns into alien and defend the earth (& his Girl) frm evil alein forces ;-) though i google "griever" and similar typo but all i get abt is FF X Villain which also Griever.