Working as a police officer in Mexico - Chapter 919 - 482:

Brolin, the nine emperor of the Black Dragon Mountain Empire, accidentally obtained the system of the realm of the world, and began the legendary journey of the battles!

In the Naruto world, with his star power, he overwhelmed the shadow-level powerhouses, grabbing reincarnation, and becoming a ten-tailed person!

Fighting the mainland, he led a large group of lords, surrounded the ancient eight clan, and confronted the peak Dou Sheng!

Covering the sky, he broke into the restricted area, seized the emperor’s scriptures and immortal medicine, and called the Lord of the human universe to fight supreme, and the sky was falling apart!

In the eternal life world, he crosses all realms, and fights against the Supreme King of Stone with the attitude of eternal true God!

Immortal continent, he jewels Jiuyang, looks down on immortal ancient, strong sky!

The perfect world, he runs across the sea, suppresses the heavens, and the Zhunxian Emperor must retreat!

Thinking of the eternal world, he ascended to the realm of Supreme Hunyuan, the fifth step of the war, Bai Xiaochun!

Heaven and earth, this is an epic of the black dragon!

- Description from uukanshu

The MC entered the body of the An family eldest son, An Ziran, an arrogant 16 years old boy who weighed 78 kg (~171-172 lbs), who only knew how to eat, play and sleep. Seeing his current body, An Ziran decided his first priority was to LOSE WEIGHT!

After crossing over to Naruto World, Shiranui Yuuji found that there was an incomparably terrifying Godzilla in his body.

“You are Tailless Bijuu? Your chakra is astonishing…. What a coincidence, so am I.”

“You know Bijuu’s coat? I don’t have Bijuu’s coat, but I do have Godzilla Coat-”

“Bijuudama is terrifying!! It can destroy a mountain as soon as he sends it down?”

Hiss, that Bijuudama scared Yuuji, he quickly moved his hands to form seals,

“Nuclear Release – Atomic Breath!”

When Yuuji turned into Red lotus form, Godzilla pressed Nine-Tailed to the ground.

“Nine-Tailed, your strength is too strong. You need to be fried…”

Nine-Tailed, “?”

“What Jinchuriki are you exactly?”

On modern-day Earth, An Lin seems to have been abandoned by God.
When his father suddenly disappears, An Lin is left with his father’s immense debt, putting his life at risk.
After being forced to a rooftop by his pursuing creditors, An Lin is unexpectedly swept off his feet and brought to the ground safely.

After learning that he was saved by an Immortal, An Lin is gifted, seemingly out of pure generosity, the ‘God Of War System,’ and a pass to a new realm.
Follow An Lin as he experiences a whole new world of legends, meets many new friends, acquires legendary weapons and tools, and starts on his path of becoming a powerful cultivator. There is never a dull time in An Lin’s new life with his ‘great’ new system!

- Description from Novelupdates