Old art.
This is X4. Before I started drawing anthropomorphic characters I drew robots and cyborgs and the like after that I started drawing dragons and also anthropomorphic dragons, so here's some pre-anthro art.

Two different type of bodies for X4.

(old) Story:
Thousands of years from now in a time where humankind already succeeded in immortality by importing their minds into a electronic brain inside a metal body a great war was going on. Two factions were fighting a war. One of them was there for the survival of humankind the other was a small group possibly even just one person with great power trying to destroy it all calling their selfs the absolute beings. Although the war itself was fought by AI based mechs Many died nonetheless yet the war went on to the point that the absolutes did the unthinkable.
The war went on outside of the earths atmosphere the absolutes had created a weapon of mass destruction. Although the fighters for survival came far the weapon fired nonetheless. A great beam of energy came out tearing trough earth itself including it's core. Earth died that day and the planet became unstable and humankind had to find another place to call home for those that survived. A new planet that could replace earth was found some years ago however, although it was not clear how to get everything to work there humankind had no choice but to go. The absolute disappeared at the end of that fight it might had also ended the war at last.
The space travel towards the new Earth took many years but eventually the first shuttle broke trough the new planet's atmosphere and touched down. At the end of the travel strange lights were seen at the other side of the planet. It was yet unknown although one thing was known of this planet and that was that it was many times larger than earth yet just smaller than a gas giant. Mining sites were built and cities were built underground. The loss was great but at least humankind had survived, for now.
At the other side of the new planet called New Earth by humankind another war between two factions was going on. This time it was a war between two alien species, one was organic and though where the others looked more like they were made out of energy. In this battle a hero of the organic faction that had great powers was captured by the energy ones. The energy life forms experimented on this one fusing the greatest powers of two factions a being that was later known as X2 was born. The energy faction used this against the organic ones.
In the middle of the battle a unknown force surrounded X2, confused it was overwhelmed and the dark power took over. Meanwhile humankind came in between the war between the new factions and the time of freedom was lost once again. Struggling once again to survive a new disaster happened. In the midst of a battle a unknown being of pure chaos and destruction appeared tearing it´s way trough the defenses of all three factions but was stopped by a mech controlled by a human. It disappeared afterwards but the one behind it all appeared once more. I were the absolutes. They had captured X2 and further modified it towards their liking Now with the name X3. Now a being of pure evil was wandered the planet´s surface. A possible weapon against it was soon discovered. Certain individual humans that possessed a unknown power that was called the heavenly soul was what stopped X3 in it´s first attack. Humans with the heavenly soul were used by having them pilot a mech along with the high advanced AI mechs. These AI mechs were made long ago to prevent human casualties in firefights and used to fight wars at that point. Not everyone liked the idea of using humans in the midst of the war itself. There was however no choice. The absolutes had to be stopped for once and for all of course they used X3 against the new forces. The battle went better than expected and X3 was destroyed. It´s body started to break apart but a sudden burst of energy coming out of X3 changed that fight. Everything around it was suddenly destroyed including the mechs with the humans inside them. A strange thing happened, a dark orb of chaos floated upwards while smaller white orbs moved towards it. The orbs fused and the chaotic orb started changing. Without hesitating the forces of the survival of humankind captured the orb and later it was planted into a robotic brain. The fusion of the orbs was later known as a soul fusion as a part of every human soldier that died in that battle had become part of this new being. The being fighting now for humankind was a soul of great power that´s capable of living inside a robotic body. It was than at last known as X4.

I can easily make a conversation in English but I´m not really good enough to write a story in English. This is a story that I came up with years ago, idk when anymore so I wrote down what I still know about it.