In Soulcalibur 6, the Soul Gauge is up on the top center of the screen, between the life bars. As fighters take a beating or deliver Lethal Hits, their meter increases to a maximum of two stocks. There are two things you can do with a stock of Soul Gauge.
To do a Critical Edge, press all three attack buttons (A, B and K) at the same time. This will unleash a character’s most damaging attack, accompanied by a particularly fancy animation.
Every Critical Edge has slightly different properties. Nightmare can plow directly through attacks with his armored Critical Edge, and Taki will disappear before she delivers hers. Other Critical Edges simply boast very fast starting speed and can punish careless opponents in the blink of an eye.
However, this isn’t an invincible attack like a Dragon Punch in Street Fighter, and (with some exceptions) it can’t just push through anything. Some characters can even be hit out of their Critical Edge. It’s a panic button, but it can fail.
To do a Soul Charge, press back and all three attack buttons at the same time. Your character should summon up a burst of energy and push the opponent away, and the Critical Meter will glow to signal that they’re in Soul Charge mode. The character will also glow, and in Kilik’s case he’ll transform outright.
In Soul Charge, fighters briefly gain a second array of even more powerful attacks, as well as enhancements to some existing moves. They also gain the ability to deal trace amounts of damage even when their opponent blocks their attacks. (You’ll see the blocking opponent glow red when this happens.)
The first use of Soul Charge is to push off an attacking opponent. The startup of Soul Charge is extremely fast — faster in fact than a Critical Edge. If your opponent is close, it will push them well out of any character’s striking range, giving you a valuable chance to take a breath and regroup. Not only can this save your life, but there’s a certain psychological effect in breaking your opponent’s flow like this.
On the other side of the coin, if you use Soul Charge when you’re far away from the opponent, you’ll actually give them an opening to approach and the initiative to attack, which is something you never want to do. Don’t pop this move out of nowhere.
Critical Edge or Soul Charge?
It’s not really an either-or situation. Critical Edge is something anybody can use with the touch of a single button. It’s easy, it does tremendous damage and it’s highly versatile.
Soul Charge is more to be mastered, as it opens up a whole new category of moves that can only be used in this short time. Whether it’s worth using really depends on how well you know your character and what kind of use you’re going to get out of the new moves. For some characters, it may well be that the massive direct damage of a Critical Edge is more valuable than their extra moves in Soul Charge, and for others the reverse may be true. It’s ultimately up to you to decide your own style.