Emotes are used to communicate with your friends or opponents during Battles. There are a number of Emotes you can use to convey your emotions of joy, sadness, confusion, and even rage!
In the "Cards tab > Emote Deck" you can build an Emote deck containing up to 8 of your favorite Emotes. Don't worry; you can still use the rest of your Emotes by pressing the white arrow that can be found within the Emote button in the Battle.
Here's where you can find them:
If you wish to mute your opponents' Emotes, simply press the Emote icon > Mute icon during the Battle.