How they compare: Ares (God of War)

Born of the king and queen of the gods, Ares was the original Olympian God of War before Kratos. Possibly due to the power of his royal godly heritage, and possibly merely due to bad luck, Ares had an inordinate amount of power even for a God and went on chaotic fiery rampages befitting his nature, stirring up warfare and destruction. Ares was the one who turned Kratos into the monster that he would become, hoping to use the Ghost of Sparta to overthrow Olympus (as each Olympian generation overthrows the one before it in turn).

In a sense Ares' plan did succeed as Kratos did overthrow the Olympian Gods, however Ares would not live to see his plan come to fruition as Kratos in his fury at the monster Ares had made him, slew the War God.

In terms of sheer power, Ares ranked as one of the mightiest Olympian Deities, implied to be stronger even then Titan Traitor Helios, whose light was strong enough to illuminate the endless underworld, and was able to destroy the world pillar, capable of keeping the above world from crashing into the underworld destroying all of creation. Both of them are much stronger then the Primordials, the body of one of whom becoming the universe, and the battle between them creating the galaxies. 

Speedwise Kratos with the released power of hope still struggled to defeat Ares, yet even with the power of hope dormant within him was able to fight evenly with the Fates, suggesting Ares scales to the Fates in speed. The Fates for the record are able to move fast enough to spin and manipulate threads for every point of the Earth every second, require-ing speeds of septillions of times the speed of light. Ares likely scales to this speed feat.

As a god Ares also possess many abilities. He can shift his body, appearing in gigantic sizes and growing 4 spidery-limbs from his back to use as weapons. He can fly and he is noted for his powerful fire manipulation. He can project fire from his weapon, grant fire-based magic to his followers, cause spontatenous combustion of his enemies, and appear in distant fire to speak to others. He also has control of Earth, able to cause massive pillars of Earth to sprout at will. Ares can also create diseases at will.

Ares abilities do not stop there. He is a powerful psionic. He can use telepathy to communicate at large distances or control his forces like harpies. He has telekinesis strong enough to wipe out entire armies and can sense distant events such as Kratos receiving the box of Pandora far to the East of his position. This is in addition to his already potent manipulative skills, which he used to turn Kratos into a monster.

Ares is able to dimensionally BFR opponents to his dimension which he controls. This is shown to be real and not an illusion by God of War 2 where Kratos goes back in time and sees his former self being sent into Ares' dimension. He can also summon his own forces, possibly due to his dimensional abilities and even summoned Shadow Clones of Kratos to battle him.

Kratos as the God of War is noted to oversee every battle that takes place across all of history when he becomes the God of War and Ares should also possess this ability, overseeing wherever there is combat. 

Ares also has the ability to strip his opponents of their powers and steal them for himself. This worked even on abilities he did not grant as it worked on Kratos' magic gifted by other Gods.

Ares at his peak also stole the abilities of Kratos from God of War 1 giving him his magic abilities including electrical manipulation, petrification and summoning intangible spirits that drain the lifeforce of enemies. 

Name: Ares

Origin: God of War

Classification: Olympian God of War

Powers and abilities: Enhanced Stats, Flight, Elemental Manipulation (Fire, Earth, Electricity), Power Granting, Power-Stealing, Limited Omnipresence (Combat), Shapeshifting, Disease Creation, Control of certain species, Telepathy, Sensing, Telekinesis, Dimensional BFR, Petrification, Summoning (his minions, shadow duplicates of enemies, and intangible life-draining souls)

Weakness: Somewhat Arrogant

Destructive Capacity: Universal+

Range: At least galactic (affected a galaxy-spanning dimension) and inter-dimensional

Speed: MFTL (Septillions)

Durability: Universal+

Stamina: Unknown, presumably very high

Standard Equipment: Sword, Armor

Intelligence: Godlike Understanding of Tactics and Strategy, Manipulative

How would he do in other verses?

In the DC-verse Ares would be somewhere between the realm of general universal reality warpers, like Post-Crisis Captain Atom and New 52 Mr. Mxyztplk, and the Pre-Crisis/Rebirth Powerhouses like Superman and Green Lantern due to his speed being between them. That said his hax is good for his tier and given his nature overseeing all combat, he could potentially avoid speedblitz. If that was the case he'd be a massive threat to the DCU regardless of what timeperiod he appeared in as his ability to steal powers would make him an immediate and massive threat to the verse. The biggest threat to him would probably be the Flash "Family" who could theoretically use the speedforce to render him an immobile statue (and they would be able to energy-drain him as they did to the Anti-Monitor).

In the Marvel universe, Ares would be an even more massive threat due to the lack of Earth-bound heroes fast on the same degree of speed and hax to stop him. While his level of hax would not be unknown, his sheer power and speed would make him rival High Tier Skyfather level entities and he could potentially beat Base Thanos in a fight. He would have enough power to potentially conquer a universe he found himself in. Above that he could possibly defeat a Cosmic Cube, likely having enough power though it becomes significantly harder to the sheer versatility of Cosmic Cube reality-warping.

Much like in the DC verse, in the Saint Seiya verse, Ares placement depends on whether his nature as overseeing all combat would allow him to avoid a speedblitz. At the very least Ares would be a high Gold Saint Tier enemy given his casual universal levels of power. While his abilities are not as versatile or numerous as high tier saint seiya characters typically, the degree of his hax including dimensional bfr and power-stealing both of which would be very strong in Saint Seiya would make it difficult for any but the strongest saints and the deities to defeat him. Assuming he can avoid speedblitz he would rank on par with lesser deities like Thanatos and Hypnos as well as God Saints.

In the CLAMP multiverse, Ares would rank as a clear god tier, nearing the absolute top. Even High Tier spirits like The Light/The Dark and The Rune Gods of Cephiro would be unable to do almost anything to Ares due to his speed versatility and just greater power. Even Ashura, the CLAMP God of War would be unable to stop Ares due to Ares' greater hax and speed. He would likely not be able to solo the verse however as someone like Clow Reed would theoreically be able to warp the concept of Ares away from across the multiverse but against almost anyone Ares would most likely win. He might have an interesting fair fight with Fei Wang Reed, depending on which arrogant manipulator is better able to manipulate the others arrogance first into letting their guard on (Fei Wang allowing Ares to enter the same general area as him and being able to affect him, or Ares allowing Fei Wang to complete his multiverse warping ritual).

In actual Greek Mythology GOW Ares would do interestingly. He is stronger then any being in the Greek Myths in raw power, easily far far faster and would smash anyone physical, however the Gods themselves are abstract entities and there is no evidence that Ares would be able to destroy them. However Ares might be able to destroy the entire physical domain and thus potentially destroy the concept. Ares would likely win or at least stalemate against most to all of the verse, save for some god tiers like Orphic Zeus who became one with the universe or the Fates both of which could manipulate fate to end Ares.