With most characters of the roleplays/series, Aura is a manifestation of emanation raw power, ki, or energy, depended from a single one's heart "and" soul. (Yes, they're somewhat the same, but uniquely different.) Auras can be used in many forms, and methods, to where it can alter speed, agility, strength, healing, magic, and other etc. Distinctively, no matter what type of power or magic one may use, it will resonate with one's soul determining on their lifestyles, attributes, personalities, traits, and what they've learned over time.
 
Auras are also used as pure armour to their skin and forms, either Physical or Spiritual, depended on the host. For the Great Four's potential of this, this aura-like armour is like a second skin, and can defend against practically anything. Deflecting bullets, heat, other powerful attacks and beyond, it is very unique, passively. However it does have limits, for if their is another with the same attributes of aura training and perhaps more, defenses can be either similar, and/or brutal, lethally.
 
Meditation is often a trait to overall species and all lives, and it is also an ability to increase and produce aura of the soul, mind, and heart. As told before it's used for healing traits, mind control, altering speed and power, strength, and can even be used for obvious destruction. On Tashki's use of meditation, and since she's a Master of Spiritual Swordsmanship and Auras, she's known to sense presences of living souls. Including other power sources, essences, and etc. And during fights, she can also meditate while fighting, making it a passive use to keep her auras stronger as progressed. However if she loses focus from any mind disrupting abilities, meditation will halt temporarily. Same applies to all others if meditating uniquely.

Tashki, Nomika, Moses and Ichimo's Auras and Abilities in Depth

Tashki, in particular may possess OP powers and all, but ultimately she mostly focuses with two essential auras: Nylos Infinitum (Legendary Golden Aura) and Aflecs Astralus (Coded Star's Cybernetic Lightning Aura). Nylos Infinitum in particular focuses on mostly strength, immeasurable amounts of mass, and the auras to become exceedingly massive sized. It does possess speed as well into having her Flash and Phantom Step with incredible speed. Same applies with Aflecs Astralus, only increasing speed, magic, and multiple atmospheres.

Though she may sound OP, like most others, she is still human nonetheless. Rumors foretell that her blood is spiritually mixed with a number of species, making her a Hybrid Human. Dragon, and Hell Raven/Angel are the mixtures, making her known to have many histories in her times of youth and legendary feats. The confusing factor of Angel and Hell Raven are surprisingly somewhat of the same tree lineage of the Forgotten Era of Gods. To when Angels have once fallen towards the cruelest hardships and survival, making them as Hell Ravens. Resulting their white wings to either conceal within their backs often, or change colour of grey or black.

With Ichimo, Nomika, and Moses to possess similar traits as Tashki, they all have learned to use Oxhale, a blessing from the unknown Fairies of a forgotten Era and managed to condone the blessing into their auras. Enabling them to breathe underwater, and in Outer Space. Their auras will become a second skin to themselves, altering not only temperatures to their Spiritual Forms against even the most frozen caves and volcanic wastelands, but also the vacuum of Space and other dimensional and celestial possibilities.

Between Tashki, Ichimo, Nomika, and Moses, they possess and have learned an ability to nullify "anyone"'s abilities, powers, and even transformed/form entities. Through the blessing Tashki's received from the unknown Eternity, The crystals that have manifested within their souls, were known as Ehrall Crystals, giving them such ability. Thus attempting multiple attacks primarily named with "Dispel", "Astral", and "Ehrall" when through multiple advantage and disadvantage chances.

As For Ichimo's side of becoming further stronger and giving a fair share with her allies, her aura has managed to become an essential for storing legendary and familiar swords from other realms, under reasons of sustaining Balance. She also obtains the ability to control Time itself. Along with speed proportions, that are bound by those existing in various realms and etc. Because of this factor, no matter how fast one may be against her, she'll always know how to turn the tables. Ichimo can even prevent anyone from entering speed dimensions and Time portals. However, her ability of this doesn't always effect any of the Great Four, Souls Beyond Gods(Dies, Assiette, and Hei for example), Nor the Souls of Evil. For if Satuzinki, a Timeless Dweller, has managed to feel Time Distortions from Ichimo, she can just re-alter it to her own advantage, locking Ichimo off, unless the tides were changed. Same applies with Tenma, Zatracenie, Mima, and so on.

On Nomika's side of auras and shared with the Great Four, her dragoon powers are uniquely known and based through the Japanese culture, by nullifying all negative status ailments, runes, and anyone's traps when they were to reach to a certain aura level of pure power.

Moses's auras are known well as a once paladin to grant the Great Four healing capabilities. By allowing their auras to not only be a defensive way for themselves but to heal gradually through time. Though thanks to Tashki, they've learned to use Cure and Elemental Magic.

Within Act II of the stories, it's been explained between Ichimo and Nomika that they, and Tashki, all three can equally share each and every one of their own powers whenever and only necessary. Though at the same time, when they're together in the field, this trait is often not needed due to all three of them, including Moses being absolutely too OP when together as it is. In other words, yes...they're unstoppable in any rate. But even then, when facing other Souls of Evil, this can vary tremendously...

For most attacks the Great Four may have, they're all often using skills inherited from other heroes and Legends long passed. But there are abilities that they do have originally made to their mastery, either way.

There've been questions about how fast one legend could be when in certain situations. And no, at this rate their stamina is almost unparalleled due to being as Spiritual Forms or otherwise. Thus comes in tactical methods they'd often use during battle.

Flash Step

Phantom Step

Astral Step

Flash Step was indeed inherited from the Realm of Soul Reapers and Hollows, but by the name itself, it was fan service named for the DBZ series. But nowadays, Flash Stepping is now a common term for moving/dashing in blinding speed from one spot to another in due haste. In Flash Stepping, obviously enough one can do this when their speed has grown incredibly fast after long periods of training or meditation.

Although as flawed as it is, it can be varied with those whom can sense presences, energies, powers, magic, etc. For instance, when another possesses too great amount of power, they'll be able to block, parry, deflect, dodge the hits, or even use their abilities as defense to take in the attacks head on.

But as for Phantom Stepping, it's a higher trait with the same speed, only that the one whom does this will have their Presence/Soul, and any source of power or otherwise hindered from being sensed in any way for a brief period of time. For until they re-appear to make surprise attacks, the hinderance wears off afterward.

Finally, there's Astral Stepping. This has only been known and used by Tashki-moniki during the Battle of a Forgotten Gensokyou against Zatracenie. By not only would her speed triple beyond even Lightspeed, but also the fabrics of Time and Space. Making her Astral Stepping occasionally, to be unstoppable, by instantaneously appearing from one spot to another, while already making the strike, along with orbs of Unknown Light burst from her previous spot. Homing towards her target. Many would recall this teleporting, but even Tashki herself has limitations... For she can only use this method of attack just a couple of times during her state of Higher Plane Soul & Existence.

After a very long time of facing endless wars for the Great Four, eventually due to Dies joining in ranks with them, the group was renamed the Great Legends since.

Because of the Legends becoming old overtime, due to them becoming too powerful, any flicker of unleashing power at their disposals, would cause many universes to be destroyed prematurely elsewhere. Because of this, it has been proven that facing any of these Legends would only cause more destruction than necessary.