Complex sentence: It can only be found in "Pokémon Ruby and Sapphire" in the grass and water of Routes 102,111,114,117 and 120, but it rarely appears, until a newsflash makes them more common.
Split into simpler sentences: It can only be found in "Pokémon Ruby and Sapphire" in the grass and water of a few routes. It rarely appears, until a newsflash makes them more common.