Certain Training Battles give you extra rewards upon winning, such as: 

• Training Battles with Chests

Some Training Battles give out Chests as an additional reward.  

This is what a Training Battle with a Gold Chest looks like.


This is what a Training Battle with a Soul Chest looks like.

• Training Battles with Magic Exams

When you see a purple ribbon below a training battle, it means there is a Magic Exam (available after Quest 1.8.3) in this specific battle.

• Training Battles with Surprise Monsters

Training Battles with Surprise Monsters are super rare in Sorcery School. 
They are full of awesome rewards. Break open them before the match ends!

💡Learn more about: Can I only play the battles I see on the Map (Training Battles)?