The source of Spawn’s power comes from necroplasm. It is the necroplasm which gives him his strength and durability. Necroplasm was originally dubbed by humans as Psychoplasm, but later in translation has become the green goo we're all more familar with. Each Hellspawn is given 9:9:9:9 units of necroplasm and when that is gone they go straight back to Hell. Spawn’s main weapon however is his symbiotic suit. His suit is called Leetha of the 7th House of K or K7-Leetha.
The suit is connected to his central nervous system which allows him to control all parts of the suit, but at times the suit has protected him even if he is unconscious. He uses the suit to create his chains, spikes and to animate his cape to attack his foes, even cutting and dismembering limbs. The costume feeds off the necroplasm in Spawn’s body however the suit can also feed off evil from humans, certain animals such as insects, bats, etc and even from different parts of the city itself. Spawn’s power is only truly limited by imagination and his units of necroplasm. However due to Spawn retaining his military training he often uses firearms instead of his powers.
Spawn also has unique powers that other Hellspawn do not have. He can detect when someone is in danger or has been killed and he can feel negative emotions such as pain, hatred and misery. It was recently revealed that Spawn’s body contained a number of lost souls. Twitch Williams estimated that their may have been near 6,000 souls in his body. He was able to summon those souls as Hellspawns anytime he needed thanks to the help from a young Hellspawn named Christopher who escaped thanks to his heart being removed early in a battle. However these souls have currently moved on, but Spawn still has their knowledge and experiences. He later shows that a few souls still remained and were the most powerful of the group but these were truly finished off by Spawn's daughter Morana.
Spawn had been given great power due to the help of the Greenworld and the Mother. He was given the power to control the Earth itself after his battle with Urizen and used this power to swallow him whole in the Earth. After giving him a piece of fruit from the Tree of Life the Mother gave Spawn godlike power. He used these new powers to engulf an army of Hellspawns in the Earth and send them back to Hell. He also used this power to destroy all of Hell and Heavens forces and the reconstructed all of Earth and it’s people and trapped God and Satan in their own realm to fight.
The First Mutation
One special power that Spawn has is mutation. Spawn first used this power when he fought the redeemer an Anti-Spawn from heaven that can manipulate energy but not powers he also has necroplasmic powers making him a tough foe. This power allows Spawn to mutate into a creature with enhanced strength this power is similar to shape shifting except he can only evolve to creatures and monsters rather than his opponents. Spawn might use this power when he trying to scare off bad guys or defeat another monster from hell.
Spawn is often known as the one because of his abilities another common reason is because spawn was brought to hell and was leader at one point and would give all other Hellspawns orders to defeat their rivals, but Spawn found out that they were evil and then decided that he wanted to leave hell and continue his mission to conquer the world. The ruler was Violator a foe of Spawn and had to fight him in order for him to leave, this was the second battle they fought but didn't last long since Spawn had fought him and learned Violator's weaknesses and used them to his advantage. Spawn won the battle then was allowed to leave. Spawn returned to earth very fast due to his speed and teleportation skills after this battle Spawn learned that he had the power to travel to different dimensions.
One of spawn's weaknesses is the Greenworld. The Greenworld is a dimension that drains Spawn's powers. Once Spawn is in this dimension all of his past starts to haunt him and starts to make him slow in combat, although Spawn still knows martial arts. When he is in this world his attacks may not be as strong. Spawn was brought to the Greenworld when he started to gain the upper hand between the battle of him and Violator, Spawn was wounded and sought a way to defeat Violator but would soon find help from the mother who helped him defeat Violator.
The Dead's Zone
Spawn is rendered powerless (and therefore mortal) in a patch of alley known as "The Dead's Zone": a small patch of Earth that is Heaven's domain and in the ethereal realm of the "Greensworld." In this alley Spawn has to abide to the laws of the Greenworld and not those of Hell or Earth.