Left (principal)

Left loves steam trains (right does too, variations included), so with his power, he builds an entire railway. His favorite is the Polar Express, so he carries the "Pere Marquete" 1225# (which even flies and can reach the speed of airplanes to travel the world) to get around. But he also likes cars, so he uses a '69 Ford Mustang.

Okay... Right's friends in the multiverse are characters from existing franchises (FNAF and FNAFHS, IT, Stranger Things, The Loud Hours, Hellaverse, and some more minor ones like Looney Tunes. Don't ask, just enjoy it). This whole thing is a gigantic, crazy crossover.

Left is the embodiment of darkness, death, and chaos. Darkness and light are the most powerful forces in the multiverse, and they reside in all of Right (light) and all of Left (darkness). They grant him certain superhuman abilities, strength, and intelligence, but nothing too outlandish. These energies provide him with these powers, but the chip, an invention created by them, is like a fusion between the Infinity Gauntlet and the Green Lantern ring. Inside, it contains an infinite number of nanoparticles (infinite thanks to the energy of darkness in Left's case, and light in Right's). The chip is located at the base of the spine, connected to the nervous system and therefore to the brain (this is fiction; I don't know if it's possible), so the wearer can create anything they imagine, like with a Green Lantern ring, without limits. But one must be specific; it's not like a wish. One must be precise, which is why one must be a genius to wield the chip. The chip also protects itself, so even if attacked by surprise, nothing happens. It also makes you immortal, revitalizing your organs despite the passage of time. The variants are limited in that they cannot leave their universes; the main Right and Left versions can, and these latter ones are more fluid in terms of power, making them more powerful. P.S. These characters are designed to be the most powerful in fiction, hence their exaggerated power.

Despite being from another universe, the main Right and Left were the first to be created, and therefore the most powerful. They have clashed, and Right has won. Right has the power to stop it, because otherwise, well, Left is darkness, chaos, death, and destruction, and no variant can stop it. Right is its opposite; it is the embodiment of light and life.

This universe is just one of many. Left can travel to these others; in each one, there's a variant of him or of Right, sometimes even like siblings. Left treats his variants as inferior and useless, preferring to work alone. New universes and variants are constantly emerging, and unfortunately for the main Left, some have fallen in love with him. Since they share his image, name, and personality, he despises them more than anything.

Left cannot feel love; his goal is to destroy and kill in other universes. He will not seek a partner; if you try, he will make you suffer. He is a psychopath, but he will never harm a child, and he will always try to protect any child in danger.