After Ten Thousand Years of Sign-Ins, I Was Summoned as a Guardian Spirit

Looking for a Novel Where the Protagonist Is Invincible and Then Gets Summoned

The protagonist should be a human from Earth reincarnated as a demon, angel, summoned beast, guardian spirit, dimensional creature, higher-dimensional being, or something Lovecraftian.

An Ancient Guardian Spirit from a Billion Years in the Future

In an era where the older something is, the stronger it is, I come from ten billion years ago, yet everyone thinks I'm the lamest guardian spirit. They'd rather choose a dog that's lived for three years than me. But they don't know it's because I'm simply too ancient.

The Protagonist Becomes a Weapon or Guardian Spirit and Gets Summoned by a Girl in the City

Novels About Guardian Spirits, with the Lead Starting at MAX Level

The Male Lead Turns into the Female Lead's Summoned Pet

The female lead summons pets, and the male lead is summoned with a System.

The Male Lead Is a Heroic Spirit Summoned Into the Fate World

The male lead is extremely powerful.

Guardian Spirit Novels Where the Protagonist Is Max Level from the Start

The kind where the protagonist is just ridiculously badass.

Looking for a Story Where the Male Lead Is Treated Like a Summoned Beast

Please, all you experts, help me out.

Any Stories Where the Male Lead Becomes a Summoned Beast? System

The more books I read, the higher my standards get.

Any Ancient-Era Stories About a Freak Who Slept for Up to 100,000 Years?

The story starts with someone sleeping for 100,000 years. When he wakes up, his Chinese has become very shabby. He fell asleep in ancient times and wakes up 100,000 years later. It's similar to a book you can search for called I, an Ancient Freak, Slept for 100,000 Years. Does anyone know which author wrote it?