Primus is the living creator-God of the Transformer race, whose body became the planet Cybertron. Primus is the twin brother of Unicron, his eternal foe, whom he battled for eons before going into stasis. Primus also created the Thirteen, the first Primes, to defeat his evil twin brother and cast Unicron into deep space.
Primus was created at the beginning of the very universe itself by the One. However, the scale had to be balanced, which resulted in the creation of Unicron, the destroyer. The two brothers battled on a deserted cyber world for ages. Still, their endless stalemate forced Primus to create the Thirteen original primes giving them the ability to transform, allowing for more possibilities in battle. Primus and the Thirteen then confronted Unicron, and eventually, by bringing the most potent spark of all the thirteenth prime close enough to the anti-spark, they managed to defeat and cast out the chaos bringer finally. With the battle ended at last Primus merged with the core of the planet by shedding his physical body and transferring his energy into the Core. Leading to the activation of the Well of Allsparks, Primus' entire body then became one with the planet which would become known as Cybertron and his spark serves as its Core, which produced an unlimited supply of Energon necessary for the continued existence of the Cybertronian race. Primus created the "Transformers" and is like a God to them as he gives them lives to live. In the early days of Cybertronian race, Primus was worshipped frequently as a god, with massive temples, churches, and monuments erected in his name but as the race progressed and advanced, the belief in Primus began to slip and eventually most of Cybertronian society believed him to be a myth along with Unicron and the Thirteen.
When the Great War began, Megatron had infected the Core with Dark Energon the very lifeblood of Unicron himself. As Primus was suffering from the effects, Orion Pax bravely went to the Core to save Primus. For his efforts and bravery, Primus gave Orion the Matrix of Leadership, which reformed Orion into "Optimus Prime". This had the side effect of unambiguously confirming God's existence to the Cybertronian people but in order to survive the core had to shut its systems down completely leaving Cybertron cold and barren until many centuries later, the Autobots were able to restore primus spark with the reconstructed omega lock.
At the end of Predacons Rising, Optimus Prime flies to the core, Primus, to become one with him and destroy the anti-spark of Unicron for ever. Primus is watching over the seemingly deceased Optimus, as it appeared when Optimus was shined on by the light of the core. This would seem to be the new transformation that Optimus mentioned as he entered the core. Optimus may return someday as his red spark can be seen flying out with the other sparks from the well.
Primus' personality is unknown but is presumed to being in direct contrast to Unicron's. It has been said by many that Primus is very wise and benevolent. Primus may or may not speak like his twin brother Unicron does, depending on if Primus has a vocal sound. Primus gives life and is a god to his creations. Many Cybertronians, including Ratchet, talk about Primus and how he gave them life.
Primus never speaks on the show, but there are flashbacks of him. In Predacons Rising, Primus was seen as Optimus entered through the Core to become one with him.
Primus makes up the core of Cybertron and Unicron makes up the core of Earth. Primus and Unicron never had a brother to brother bond. Since they're opposites, they fought countless times. Primus is purely good and Unicron is pure evil.
Primus's power is equal to that of Unicron. It has been shown that by his will alone he was able to create three species and manifest pure Energon. It is said that he possesses, like Unicron, a form of pure energy and can shed his physical body which Optimus stated, he already has. He presumably possesses any powers over Energon and Cybertron that Unicron has over Dark Energon and Earth.
He possesses the ability to directly transmit information to another individual's mind as long as Energon flows through them, mirroring Unicron's ability with Dark Energon.
When Optimus Prime entered the Core to support life on Cybertron, Optimus was merged with Primus. Light shined on him as he went deeper into the Core. This allowed Primus to give life again and millions of sparks burst from the Well. Like Unicron, Primus likely possesses the ability to revive anyone who is dead, as Optimus was able to briefly return to life to defeat Underbite and speak to Bumblebee and his team in Robots in Disguise, possibly due to Primus. Also, Optimus's statement about "the universe" having plans for him in the future, may refer to Primus.
- Optimus Prime is the first Cybertronian in history to have ever met Primus, the second being Windblade. Soon after the Matrix of Leadership was given to Optimus, Primus remained "dead" for some time until Team Prime took over the Nemesis and used it's Omega Lock to restore Cybertron. Primus was fully restored after Optimus sacrificed himself to bring life again on their planet.
- Primus appears in Transformers: Robots in Disguise.
- Primus shares similarities with the Great Dragon from the Winx Club franchise
- Primus is an ancient God of Good Order Life Creation Light Midnight and Day who originated at the dawn of the universe
- Similarly, the Great Dragon is an ancient god of good order life creation light midnight and day who originated at the dawn of the universe
- Primus' twin brother is the God of Evil Chaos Death Shadows Destruction Disgood Disorder Dislife Discreation Dislight Night and Darkness, Unicron, who is also his opposite, with Primus representing good order life creation light midnight and day while Unicron represents evil chaos death shadows destruction disgood disorder dislife discreation dislight night and darkness, and their continued existence is considered necessary for the existence of the universe.
- Primus later became the planet Cybertron, the homeworld of the Transformers, and his name is invoked religiously by both the Autobot and the Decepticon factions of the Transformers.
- Similarly, the Great Dragon's opposite is Darkar the Shadow Phoenix, with the Great Dragon representing good order life creation light midnight and day while Darkar the Shadow Phoenix represents evil chaos death shadows destruction disgood disorder dislife discreation dislight night and darkness, and Professor Wizgiz implied in Season 2 that their continued existence is necessary for the balance of the universe.
- The Great Dragon later went to rest on the planet of Domino, and its name is invoked with high respect by both the Fairies and the Witches.
- The essence of Primus is contained in the Matrix of Leadership, which Unicron seeks to obtain so he can reach his goals.
- Similarly, the essence of the Great Dragon is the Dragon's Flame, which the Shadow Phoenix seeks so it can reach its goals.