Funny thing is that 90% of the original posters who asked the question don't even bother reading what they posted...
The cards/characters of Urban Rivals are seperated into groups called clans. Each clan has a Theme and a bonus (Example, Jungo's theme is humioid animals and their bonus is +2 life).
To activate a card's bonus (say, Scotty), then another character from that clan has to be 'in your hand'(aka one of the four cards while playing). That means if you have Scotty and Rodney (another Jungo card) in your hand, both of their bonuses are activated/
To help stop any confusion, I classified the bonuses to see if they visibly effect your card, your opponent's card, or neither.
Effect You: Bangers, Fang Pi Clang, Frozn, Jungo, Junkz, La Junta, Rescue, Sentinel, and Ulu Watu.
Effect Your Opponent: All Stars, GHEIST, Montana, Nightmare, Piranas, Pussycats, Sakrohm, Uppers
Neither: Berserk: If activated, your opponent's life points get reduced by 2, with a min of 2.
Freaks: If activated, your opponent is now poisoned (loses 2 life points EVERY TURN with a min of 3)
Leader: If activated, YOUR Leaders' abilities are deactivated (NEVER have 2 leaders in your hand).
Skeelz: If activated, Skeelz's abilities cannot be stopped by Stop opponent Ability (GHEIST and Roots bonus).
Vortex: If activated, when a Vortex card loses the round, you get 2 out of 3 pillz back (with a min of 1).
Note: If a bonus affects attack (Junkz, Montana, Rescue, Sakrohm, Sentniel, Uppers), it gets added after the attack is multiplied: (pillz x power)+/- bonus