Light sport aircraft student pilot reported an NMAC with a light aircraft during maneuvering practice in the Long Beach Practice Area.

Narrative

My CFI and I were in the Long Beach Practice Area doing ground reference maneuvers over Angel's Gate. We were doing S-turns and turns around a point. We performed clearing turns each time and made regular position reports on the CTAF with our location and intentions. We coordinated with a helicopter and Aircraft Y in the area to stay out of each other's way. We conducted these maneuvers for probably 30 minutes with no issues. Aircraft Y was also in the area on the frequency that whole time; and began to do the opposite of what he was announcing on the frequency. He would consistently make U-turns and fly directly into our flight path; at the same altitude; forcing us to abandon our maneuvers and even at times take substantial evasive action. The most egregious case was near the end of our flight block. They came towards us; same altitude (1000MSL); and appeared to be trying to freak us out. We dove to 600 MSL to avoid them. They ended up passing directly over us at the altitude we were at previously. This pilot was either extremely oblivious or deliberately trying to mess with people. It was weird because he was on frequency and responsive; but pretended nothing was happening every time he got near us and made us abort our maneuvers to avoid him. This kind of behavior was repetitive enough and egregious enough to report.