What is the Source Wall?

It can be considered a shared Cosmic Consciousness in the DC Universe, where it is the non-religious equivalent to Buddha nature. It is the "source" of all that exists. Alternatively, it can be considered a description of the Creator of the Universe, a science fiction analogue based on Judeo-Christian doctrine. Mostly associated with the New Gods, the Source was the supposed origin of the “god-wave” that is believed to have been responsible for creating and empowering the "Gods" of the DC Universe with their divine abilities. It also seems to be partially responsible for the ability of DC residents to develop super-powers, especially those which defy physics. Lying at the edge of the known universe in the Promethean Galaxy is the Source Wall, which protects the Source, and traps all those who attempt to pass beyond it. Very few have interacted with it outside of Highfather of the New Gods; therefore, not much is known concretely about its many aspects.

Now that the DC Universe is revealed to be 52 universes it is stated that each reality has a Source Wall separating it from the others with The Bleed in between them. Superman-Prime managed to destroy a Source Wall causing the destruction of Earth-15. The Monitors caution that passing between realities breaks down a Source Wall and eventually other Earths could end up like Earth-15. During the Twilight of the New Gods, it is seen that the New Gods are no longer passing on to the Source and instead they are forming a second Source Wall as the God-Killer is stealing their souls.

While investigating the death of the New Gods, Metron encountered the Source. The Source revealed it was behind the deaths to build a new "Fifth World." It revealed that the most powerful gods of three pantheons of the Third World--the "Old Gods"--attacked it and caused it to split into separate beings. The other being evolved into the Anti-Life entity. In retribution, the Source destroyed the Old Gods and created the New Gods. However, its diminished state caused the New Gods to be flawed. The Source seeks to reunite with its other half and start anew. It has apparently manipulated several beings such as Alexander Luthor and Rip Hunter, as it never resided behind the Source Wall, to create the 52 worlds of the multiverse to ease the reunion.

Following the Teen Titans defeat of Superboy Prime, he is imprisoned in the Source Wall by Superboy and Supergirl, citing it was the only place they could put him he couldn't break out of, since he has breached both the Phantom Zone and escaped the Green Lantern Corp's custody previously.

Who Makes Up The Wall?

1. Yuga Khan: Darkseid's father attempted to breach the Source Wall, however, like many others who have tried, he was imprisoned.
2. Ligea: Ligea was on the wall and freed by Orion. After her freedom she tricked Orion and tossed him to the wall. Once she escaped the wall her image disappeared.
3. Orion: Orion was not fully apart of the wall as he was able to escape with the help of the mother box before it closed in on him. He believed he was able to escape because he did not truly intend to breach the wall.
4. Ares, god of war, once attempted to breach the wall for the powers on the other side by was like all others trapped in it, how he escaped is unknown.
5. Darkseid: After seemingly killing Supergirl, an enraged Superman seals Darkseid into the Wall. An alternate version of Darkseid later helps Superman and Batman correct their altered timeline and in return Superman removes Darkseid from the Wall.
6. Superman: When Superman releases Darkseid from the Wall he is thrown in himself, until a group of alternate Supergirls help free him. He is imprisoned again by Desaad, but Batman help to free him.
7. Gog: The last survivor of the Third World was thrown into the Wall by Superman in order to save the Earth from his influence.
8. Superboy-Prime: After attacking the Teen Titans, he is sealed in the Wall as the only means to finally imprison him.
9. Doctor Doom: He is sealed in the Wall during JLA/Avengers.
10. Relic: At the climax of Lights Out, Relic is taken into the Wall by Kyle Rayner. While he passes on to the Source, Relic is sealed in the Wall.

Some have managed to pass the Final Barrier and entered the Source, all viewing it differently:

1. Lucifer: A huge, yellowish man made of rock.
2. Hal Jordan as Spectre: A giant Green Lantern battery that was likely the embodiment of willpower. Jordan felt as though a part of himself was still in the Source.
3. Barry Allen: Unremembered, his sole purpose was to find a cure for the New God, Orion.
4. Superboy-Prime: During the events of Countdown, where he was trying to find his own Earth in the Multiverse, the even more powerful Superman-Prime is able to easily blast through the Source Wall with his heat vision and completely destroy whole universes on the way.
5. Superman: Once mind controlled by Desaad and sent to retrieve the staff of the Highfather of New Genesis in an effort to re-ignite Darkseid's Omega powers that were lost after his time in the Source Wall. While beyond the wall Superman encountered what he thought was Highfather's spirit who guided him back to Batman, Bekka and his staff, allowing Superman to escape.
6. Lex Luthor: In Justice League Unlimited Lex travels past the Source Wall in order to find the Anti-Life Equation and stop Darkseid's attack on Earth, though Metron warns him that only a 12th level intellect (the highest level in the DCAU) had the slightest chance of surviving, something Metron himself wouldn't risk, Lex on teh other hand calls himself over qualified and leaps into the wall to be confronted with the strange sights and sound on the other side.
7. Kyle Rayner: At the climax of Lights Out, Kyle took Relic and himself into the Source Wall. While Relic is fused to the Wall, Kyle is able to reach the Source itself. While there, Kyle not only completes his mission to replenish the Emotional Spectrum, he also inadvertently alters the Source, leading to the creation of his enemy Oblivion, and the taking of the Life Equation into himself.

Alternate Versions

New Teen Titans/Uncanny X-Men: Apokalips now

In the non-canon story of the meeting between the New Teen Titans and Uncanny X-Men, the Source Wall played a role similar to the M'Kraan Crysta l and served as the barrier which the Phoenix Forced live behind, only from the perspective of the Fourth World. As a part of his ploy to conquer Earth, Darkseid had first absorbed the X-Men's memories of Phoenix before collecting residue and data from sites where it had manifested in the past (like in New Mexico, though that site was ultimately foiled) before he summoned a Dark Phoenix from beyond the Source Wall. Before this, he had Metron enter the Wall, leaving his Chair behind, thinking him gone for good. Ultimately Darkseid is defeated and a sliver of Jean Grey awakened in Dark Phoenix who proceeded to attack Darkseid before carrying him to the wall, leaving him embedded in it while Metron emerges from it and reclaims his chair, claiming it was an interesting experience.