Flux

Origins
Flux, or Rhys Scott, was created by the Elders, to be one of the Guardians of Eden. Eden thrived in perfect harmony for millions of years before the corruption. It was stronger than the Guardians and latched onto anything it killed.

When the rest of the Guardians were corrupted, he was the only thing stopping the corrupted from reaching Eden. He had to adopt new tactics as he couldn't fight them head on, refining his energy to strike fear into his enemies. He was shunned by the Elders for the use of these tactics, being driven out of Eden.

Eden fell three days later.

In a last ditch attempt for one of the Elders to salvage the universe, they closed off the universe, sending everything else to a new one, free from corruption.

In the new universe, Flux wandered around, purposeless. For the first few billion years he hunted for traces of corruption, before settling down. He tried to eliminate threats from the shadows, remaining hidden for the rest of his days. Once the universe ended and reset, Flux had been carried over as well, essentially a loop. After the first couple of universes Flux began to care less and less. After the first 10, he did whatever he wanted, wiping out entire civilisations just to pass the time.

Powers
Flux can tap into an [unnamed] energy (am lazy) which allows him to travel to the Realm Between Realms, summon weapons and armour. The raw energy is green. It is uncontrollable and volatile, but incredibly powerrful. It cannot be used to make weapons without incredible power, something Flux could only do until the end. The energy is the only thing that rivals the slayers. The refined version glows gold, it's less powerful, but can be made into anything, including a shroud over his armour.

Flux's armour can survive any environment, without the help of a shroud. It is imbued with Flux's energy, allowing him to absorb any hits and strike back with the same force.