As long as Ursaring is your Active Pokémon, your opponent's Basic Pokémon can't attack or use any Poké-Powers.
Before doing damage, you may switch 1 of your opponent's Benched Pokémon with the Defending Pokémon. If you do, this attack does 20 damage to the new Defending Pokémon. Your opponent chooses the Defending Pokémon to switch.
Flip a coin. If heads, this attack does 40 damage plus 20 more damage.