The only one I can think of off-hand is Stephanie V. from Redemption Island. She was the one who tried to be Russel 2.0 (with an emphasis on the zero).
Other villians I can think of that made it just past merge but no further are Rocky and Lisi from Fiji.
Laura M from Somoa and Randy from Gabon got into the jury stage and I think were second or third on the jury.
J.P from Cook Islands was annoying and bossy but not a full-blown villian.. he was out pre-merge, I think.