Complex sentence: Each of these status conditions negatively affects how the afflicted Pokémon performs in battle, from simply damaging the Pokémon over a long period, to not allowing it to even attack for one or more turns.
Split into simpler sentences: Each of these status conditions negatively affects how the afflicted Pokémon performs in battle. This is accomplished by doing anything from simply damaging the Pokémon over a long period, to not allowing it to even attack for one or more turns.