Until the end of your next turn, if an attack damages the Defending Pokémon (after applying Weakness and Resistance), that attack does 20 more damage to the Defending Pokémon.
[F][F] Rage: 10+
Does 10 damage plus 10 more damage for each damage counter on Onix.
It twists and squirms through the ground. The thunderous roar of its tunneling echoes a long way.