The requirements and tips for this Achievement are the same as they were in
Earthlock: Festival of Magic. For reference you can find solutions here:
Text from D4rkTrooper90's solution below:
To obtain a gold medal you must group all enemies together on each round and fight them all in 1 big battle.
Whenever possible wait for the enemies to walk close to each other before engaging them and be careful when you have to pull one group to another as it's easy for some enemies to fall behind and mess your whole run up.
Some extra notes for this version of the game:
> Olia's overworld ability (Taunt/Shout) can help ensure that you trigger all enemies in the area. Keep mashing
once you're ready to fight and press
once the enemy count covers all enemies in the current Round.
> I would recommend your battle party be at Levels 10+ for the Zaber Tournament.
> I would recommend your battle party be at Levels 13+ for the Suvia Tournament.
> Multiple party configurations are viable, but an easier one would be Gnart/Taika + Amon/Olia. Have Gnart use Magic Focus to buff Taika's AOE abilities and use Heal S to full-heal the party whenever required. Amon/Olia can take care of enemies with physical attacks and Blaster S is also useful.