MTL - Marvel: Trading From the Ninja World - v2 Chapter 324 Gathering Church

16 years old-- most boys would be falling in love, as their hormones all rise to unprecedented levels. Most boys at Riley's age would have dreams; dreams that will slowly grow into passion. Riley, however, at age 16... killed the world's number 1 superhero.

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

mc gets transmigrated to Fallout New Vegas with the merchant system. let the questionable adventure begin.

An unexpected discovery in Machu Picchu has transported a young professional thief from Earth to a world filled with mystical powers and evil plots. With his beloved teacher and best friend killed during the calamity, his only goal is to become stronger, so that he can take revenge for them.This is a novel filled with politics, the struggle for power, evil beauties, and of course, Divine Immortals.

- Description from Novelupdates