It was never stated that Cesar was the 'leader' of the Varios gang. But yeah he is cool, CJ's best friend throughout the game. That mission was called "Los Desperados".
The Truth is the best, he knows everything; and he's more interested in that place 'off of the map'. He's the perfect role model. ;)
South Park, Charmed, Buffy The Vampire Slayer / Angel, Tru Calling, Family Guy, TrippingTheRift, FreeForAll, Futurama, Jackass, Lost, That 70's Show, Celebrity Deathmatch