Solus Prime

Solus Prime is one of the Thirteen created by Primus. Solus is a female Prime and is the maker of ancient Cybertronian weapons and relics. The arsenal of magnificent weaponry and icons wielded by the original Primes are her most impressive handiwork, created by an icon of her own, the Forge of Solus Prime. She finds joy in creation, which is why she's particularly close friends to Nexus Prime, Micronus Prime and Onyx Prime who revel in similar pursuits. Her closest relationship however is to Megatronus. The two are bound by a close devoted romantic love unique among the Thirteen and spend much of their time rejoicing in each other's presence.

Solus Prime design is regal and silver and black.

She is noteworthy for not only being a skilled creator but being the first and so far the only female Prime.

History
Solus Prime was among the Thirteen created by Primus to battle Unicron and given a hammer she named after herself. After all the stellar cycles Alpha Trion had no idea why Solus was female but the other twelve were all male. He suspected it was due to Primus wanting to increase diversity in the species. Since Solus was the only female Prime, there would always exist one female Cybertronian for every twelve male.

After the battle she became close to Megatronus Prime and had a rivalry with Prima. As he was creating war beasts, Liege Maximo asked her to make him armor. She made the Apex Armor but was hesitant to give it to him even after he showered her with gifts. He tried to manipulate Megatronus into getting it for him, but this led to a lover's quarrel which ended with her being accidentally killed by the Requiem Blaster. She pledged her undying love to Megatronus before she died. Prima tried to use this to rally his brothers against Megatronus only for Megatronus to confess about Liege's work. After a bloody battle, Solus' corpse was placed in a beautiful tomb forged by her remaining brothers. Eons later, a semi-sentient hologram of her spoke to Optimus Prime. She told him where he could find the Requiem Blaster and gave him subtle hints that Nexus Prime was near.

Transformers: Robots in Disguise
Solus Prime never makes an appearance but her name is mentioned numerous of times by Fixit and Strongarm. In Battlegrounds, Part 2, Fixit notes to Bee's team that Solus Prime was destroyed by Megatronus when he turned on his fellow Primes with no mention of their relationship.

Creations
Solus Prime has created many legendary powerful items, including:
 * Forge of Solus Prime (named after herself) (destroyed by Predaking)
 * Star Saber (with Optimus)
 * Requiem Blaster
 * Chimera Stone
 * Apex Armor (in Miko's care)
 * Infinite Combinatoric
 * Chaos Edge
 * Cyber Caliber
 * Quill

Trivia

 * Solus was beloved by most of Thirteen except Prima, who shared a mutual hatred with her.
 * While origins of the Thirteen differ from the various pieces of media regarding them in the Aligned continuity they all agree that Megatronus murdered Solus. The difference is that in the novels he wanted absolute power and if Solus would not stand with him she would have to die while the Covenant presents them as star-crossed lovers. And Robots In Disguise makes no mention of any relationship.