it is now possibly to get a latios if u have latias and the other way around go to seribii net and click current events on the left side it will give u a stone go to the market talk to the green man then go to pewter city musem go to the right u will see steven he will talk to u later go out side to the left u will see latios heart gold latias soul silver talk to steven then save go fight and capture ur pokemon if u want it