Shizuru

"Nobody will save your soul now." - Shizuru upon defeating Veldanava

Backstory
In the days leading up to Shizu's death, her and Rimuru grew close together due to their bond as Japanese. After Kaval and the other adventurers would go to sleep, Rimuru would bring Shizu to a secluded area in the Jura forest that overlooked the forming capital of Rimuru and they would "bond" together. When Shizu passed away and was eaten by Rimuru, he noticed that there was a fertilized egg that he had consumed, and took it upon himself to keep it safe. The egg was looked after by Veldora and Ifrit before their release, and it has been kept inside Rimuru until Shizuru evoled into a True Dragon. When Rimuru finally let it free after his battle with Veldora and Velgrynd, Veldora and Charys named the child Shizuru after its parents. Obviously, it was kept a secret from Rimuru's adujants. The child is half-slime and half-human, meaning that it is a rather viscous form in a human's shape.

Strength
Because of Shizuru being inside Rimuru's stomach with Veldora and Ifrit, it eventually evolved into a True Dragon. Technically speaking, Shizuru is the 6th True Dragon behind Rimuru. Due to being named by such powerful beings, Shizuru was given the Ultimate Skill "Fertilized Egg God: Tama". The extents of the power of the Skill is unknown, but Shizuru easily bested Benimaru in a mock battle in Tempest's Colosseum. Due to the nature of beating a True Demon Lord that easily, it was given a Special-S rank. After some time, Shizuru also manifested a Manas due to Ciel and Rimuru's influence upon it. 『Manas: Samuel』 was created, which was something akin to Ciel's own offspring.