Transmigrate inside a Web Novel as a Side Character. - Chapter 1 - 0 Transfered into a Novel World.

I dedicated 10 years of my life, focusing solely on regression.[Authority: Death Regression has naturally been nullified.

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

There are three realms in the multi verse; The Cosmic, the Mortal and the Nether realm.

Hal grew up in the mortal realm with no idea whatsoever of who his parents were.

His love for relics, adventure and the occasional danger would aid him in finding a genie's lamp.

Rubbing a genie's lamp should grant three wishes, but Hal is struck by lightening instead and eventually arrives in the Cosmic realm with a large book in his mind space titled; The Primordial Cosmic Grimiore, that apparently holds all knowledge for a perpetual reign.

And so Hal's journey begins in a little city called Salmon city, in the body of a 17 year old boy also named Hal but was sold into slavery by his own father.

Hal finds out who his mother (prior to reincarnation) whose bloodline now flows unmixed in his new body is....

Join Hal as he battles mortals, Dragons, phoenixes, Gods and many more together with his harem of Beauties for the complete subjugation of the three realms.

Other people earn points, gain skills and attributes after transmigration, while I end up planting trees?