THE BACK STORY OF THANOS
Thanos was just a little boy when his parents had died on titan, his birthplace. You see the population on titan has for more advanced technology and bionics almost 1/4 of the population on titan were cyborgs (half human half robots). But none of the population understood the definition of being kind, generous, and helpful. Titan was filled with the biggest and cruelest species ever. To start a full-fledged war it merely took to people to accidentally bump into each other.
Now coming to the point Thanos’s parents were missing in action after a war that killed many people. This left baby Thanos to fend for himself. No matter how heartless the people of Titan were, no one could allow a baby to be killed directly, so someone came up with the idea of leaving the baby’s on a rock in a forest, as this would mean that they weren’t directly killing them. Most of the babies with missing parents got this treatment including Thanos. Now, most of the babies died but Thanos had no intention of doing so.
Did I mention that there lived many griffins (half man half horse)in the forests of titan? The centaurs usually hated the people of Titan for cutting down the trees but they took pity on the babies and looked if any had survived and you can guess that the only survivor left was Thanos. From that day on he was raised by the centaurs. He learned everything that he needed to learn from the best of the centaurs. He was taught many methods of wrestling and usage of weapons such as swords, clubs, bow and arrows, javelins and spears.
Thanos has grown up amongst the centaurs, who have usually lived in peace except when they were fighting for resources. This is where Thanos had understood that the world needed correction as the world did not have enough resources for all living beings. As soon as Thanos was old enough he started tricking some very strong titan people to turn against the rest. As soon as he had a big enough army he had killed everyone on Titan, and as soon as he had done this he and his army had taken a spaceship and killed half of each planet they saw, after every planet they defeated, the stronger they got. When the killing was happening Thanos himself went into the battlegrounds to pick a few recruits to the army.
So this is a backstory I have written to explain why Thanos wanted to kill half the universe.