Neutrality Sue

What happens when you have a Purity Sue, and remove the Purity part? You get a Neutrality Sue. This one, much like the Anti-Sue, is not afraid to be flawed. In this case, however the distinction made is not that the character is trying to be flawed, but that any flaws are Hand Waved by them being neutral characters. But, here's the interesting part... this means they have license to do anything. Want them to save a kitten from a tree? They can. Want them burn the tree in the very next moment? They can, with no contradiction of character.

In terms of personality, this trope usually is either devoid of emotion, or varies from deadpan to emotional to outright unstable. The Neutrality Sue basically thrives on being somewhere between extremes, and thus able to do everything in between.

The Heroic Neutral, the Nature Hero, Badass Normal, and the Red Mage are all good candidates, if they're taken Up to Eleven, the only one of their kind, and their effects can't be suppressed or countered. Expect them to have Power of the Void, a Hand of Life/Hand of Death, and Yin-Yang Bomb as their power. Usually the protagonist, since as a secondary character their power is usually downsized.

Related to the Fixer Sue, a combination of Purity Sue/Villain Sue, and in some cases the Sympathetic Sue (if backstory and personality flaws are played out heavily).

If the character is a Yin Yang Master, but fits smoothly within the party, they are probably another trope. If they affect the whole balance of the good and evil within the universe, or are the only defender of nature, and without whom the universe suddenly and inexplicably collapses due to the natural laws being disordered, then they might be this trope.