Michael : Kraven may still have his men with him. You're not going alone. Selene : He's not as strong as you might think. Michael : What? Selene : Michael, you're unique. There has never been a Hybrid before. Not to be ambivalent about it, but the truth is your powers could be limitless. You depend on blood. [Selene retrieves a plastic bag of cloned human blood from a medical cabinet, Michael is visibly unsettled] Selene : You need to feed. Without it, you'll be growing weaker by the second. Use the time for that. Michael : What if I don't? What if I can't? Selene : Normal food could be lethal. If you don't anticipate your cravings, you will attack humans... and believe me, you don't want that on your conscience. There really is no going back, Michael. I'm sorry.

http://www.moviequotedb.com/movies/underworld-evolution/quote_40947.html