1) Go to practice mode.
2) Choose a character with an easy to perform Rage Art. (I used Katarina as hers is just
) Opponent doesn't matter. If you fancy a different character though or find pressing
too difficult, pressing
with any character will also perform a Rage Art.
3) Once practice has loaded, open the pause menu and navigate to the Other Settings
4) Turn on Player Rage
5) Now unpause the game and activate you're rage art 20 times for the achievement!