SSS Cultivation: I Can Conquer Earth's Rank System

Taking a quick peek into life on normal planet earth, a vicious alien race called the Xollante attacked the planet with their nuclear weapon. But that's not the story... Shortly before the alien attack, the story was based on an orphan boy named Leo Rayden who somehow discovered that he possessed interstellar communication ability. With this ability, he communicated with a being from a planet friendly with Earth. The being told him that he must warn earthlings of the attack from the Xollante race. But Leo saw himself too young and too weak to carry out this assignment. So, neglecting the warning, the Xollante finally arrived on Earth's atmosphere and just like that, Northern Earth became destroyed... The Space Guardians of Earth couldn't stand the almighty Xollante fleet. And to make matters worse, Earth's core became weak and split. But that is still not the story... A second era now was set in place after the nuclear attack. Earth became split from the core after the nuclear attack and slowly, the Northern and the Southern part of earth started drifting apart. The wild Xollante race occupied the North, while the surviving earthlings occupied the South. But now Earth must do everything to destroy the Xollante race and send them away from the planet. And that was when another scheme was set. Earth had discovered a Lone and barren mutant planet called Luxus which gifted earthlings with superpowers. Humans call these superpowers "Quirks". So, for the grand scheme, Earth's authorities started sending men and women on the planet to become mutated in readiness for the huge war that was looming against the Xollante. Earth was now full of mutants, and soon enough, non-mutants became outcasts in the society. The system only favoured the powerful and scorned the weak. And that was when Leo woke from his coma of 78 years on planet Luxus. And this, guys, is where the story starts... Leo managed to survive the nuclear attack with some strange hidden quirk he didn't know he possessed. When he opened his eyes 78 years later, he was on planet Luxus, being taken care of by his mind communication partner, Loca. But there was no time to frolic. He has to get back to Earth and try to rediscover that powerful quirk that saved him from the nuclear attack. To do this, he must attend Earth's quirk academy to learn all he needs to get stronger. He knew somewhere within him lies the most powerful quirk ever in existence, and his only aim is to rediscover it. He must become stronger, beat earth's power system and one day help the top earth Avengers fight off the Xollante race. But first, he must overcome every obstacle thrown at him from his fellow Earthlings and fellow mutants before he could even think of fighting the aliens. He must attain the highest rank level possible to atone for his sin as a child for not saving Earth when he was informed. His guilt being the major drive, he soon found that the highest rank was within reach of him, but can be pay the price? This story incorporates the use of hi-tech weapons and ancient weapons, and the use of acquired quirks to wield these weapons to victory. It is truly a story about weak-to-strong, action, survival, mutants, adventure, academy and superpowers. A mix of sci-fi and fantasy, yes. And yes again, local beast weapons have been smuggled into sci-fi. Let's deal with it.