Complex sentence: Mightyena in Pokémon Ruby and Sapphire is only available by evolving a Poochyena but in Pokémon Emerald, it can be caught on routes 120,121 and 123.
Split into simpler sentences: Mightyena in Pokémon Ruby and Sapphire is only available by evolving a Poochyena. It is widely available in Pokémon Emerald on Routes 120,121 and 123.