The Basics of Gauge Attacks
Soul Gauge
Your soul gauge increases when you attack, make advancing movements, and so on. Use one bar of your gauge to perform advanced moves and unleash powerful ones.
Characteristics of the Soul Gauge
You have up to two bars.
Landing a reversal edge increases it dramatically.
Additionally, when you take damage, the bar increases slightly.
Soul Charge:
+ 
Uses one bar.
Temporarily increases your abilities.
• Increases your attack damage.
• your attacks damage your opponent even when they guard.
• You gain access to soul-charge-specific moves.
• The battle timer stops, meaning time won’t run out.
Additionally, some characters have access to hidden moves.
Critical Edge: 
Uses one bar.
An extremely powerful move that each character possesses.
Some characters have access to two types.
Soul charges and critical edges vary from character to character. Knowing these differences will help you in battle.
It is recommended you read the combat lessons to learn more: go to “Museum”, then “Combat Lessons”, followed by “Universal Tactics”, and then “Individual Characters”. From there select, the soul charge or critical edge lessons.