For this I think it'd be cool to see metal bending or lava bending for minigames. The reason it'd be cool for minigames and not combat would be because if someone could lavabend or metalbend, or both depending on how its done, it would mean the match would be over super quickly. Giving the ability to use them in the minigames area would be super fun and you could see if at any point the moves could be used in pvp. For lava bending you could have the classic lava floor, lava disc, and lava throw for its only abilities. As for metal bending, you could have the metal bender cables that they use in korra, metal armor which gives you additional health, and the ability to shoot off the armor as a projectile