Background:
Catalina Viapalando is the cousin of Aztecas gang member Cesar.Catalina grew up in South Los Santos alongside Cesar.With Colombian roots
GTA III:
Catalina first appears in GTA III in the oppening cutscene when she beatrays his boyfriend Claude who is the protagonist of GTA III.After the beatrayal she works with the Colombian cartel(she worked with them before the first mission aswell) who are at war with the azuka.Claude evetaully gets revenge on Catalina resulting in her death.
GTA San Andreas:
Catalina's first apperance chronologically is when CJ comes to see her after Cesar recomends him to do that(after he is forced to stay in the badlands),her first apperance sums up pretty well who Catalina is when she's threatning a guy with a knife at the bar she's at.
CJ does a bunch of robberies with Catalina mostly being betting shops and smaller stores,one robbery in particilar is when they rob a betting shop and have to flee the local police department that woud have costed Catalina's life if not CJ was allong.This also shows how narcisistic Catalina is beacuse after the mission Catalina dosen't thank him at all.Catalina and CJ's relationship is problematic and CJ soon realises that she ain't the buisness partner/girlfriend for him.the last apperance for Catalina in GTA San Andreas is on Farewell my love when she tells CJ that their work was only for buisness,and that she has found a new man in Claude the protagonist of GTA III.The mission is a race through the badlands against Claude and some other participans.After the race Catalina and Claude leaves for Liberty City,Catalina expekt him to get mad at her and try to fight for her but CJ insted sais this "I coud take rejection" and they both say that they won't miss eacother.
Personality:
Catalina is a psychopath,wich in short means that she can't show emotion for others,and woud betray anyone for her own benefit.What makes Catalina different from other psycopaths is taht she is also very narcisistic and can't show respect and admire pepole.