How does the opponent AI work during battle?

Whenever a battle occurs automatically, Sync Pairs will use moves that deal the highest damage. These are usually the ones with the higher move gauge requirements, thus it gives you more idle time when they're charging up.

If you are in battle, you'll want your Strike Pokemon to survive longer since they are the main damage dealers. Strike roles usually do not have the best defenses and you won't want them to be defeated fast.

In Pokemon Masters, opponents will attack the Pokemon with the highest combination of HP, Defense, and Special Defense. You can view your Pokemon's stats before starting a battle and compare them.

In this battle for example, Rosa and Snivy have the highest combination in those stats. The target is locked on to Snivy only and they do not change targets. Use this to your advantage if you have specialized strike pairs with you. It's best to use a good support Pokemon if you want to have it as a tank since some even have healing capabilities.