This was done by a professional game hacking company which used cheat codes to unlock mega evolutions and shinies for these legendary pokemons. Both retain their original typing and abilities.
Mega Latios 80 HP / 130 Attack / 100 Defense / 160 Sp. Attack / 120 Sp. Defense / 110 Speed Mega Latias 80 HP / 100 Attack / 120 Defense / 140 Sp. Attack / 150 Sp. Defense / 110 Speed.