i just beat 3 of the 4 maps in merc mode. i got 4 stars, and i unlocked ada, hunk and wesker. all i have to say is HOLY CRAP, WESKER! he is really good to use. gets a silenced handgun, killer 7, and rifle to start with. his up close attack is aswome too. HUNK is a pimp too. he snaps necks when he is up close. i still gotta unlock krauser though. but to do that, i gotta get 4 stars on the castle map, and that is a tough one.