Who is the antagonist in the novel, Incantation?

Catalina is the sixteen year-old antagonist in the novel. Catalina is, on the surface, a sweet and simple girl, yet she has ulterior motives and an inferiority complex which leads her to believe that Estrella thinks she is better than everyone else. Ultimately, Catalina and Estrella grow apart, including after Catalina and her mother denounce a neighbor in court, only later to raid the neighbor's house of goods. Catalina has plans to marry her cousin, Andres, but Andres falls in love with Estrella. Out of jealousy and anger, Catalina turns in Estrella and her family to the authorities. The last Catalina sees of Estrella, Estrella places a curse on her to feel the pain of others until Catalina understands what she has done.