U-Ban is a Kryptonian and has two brothers Kizo and Mala. U-Ban has blonde hair, wears a white bandana, and wears a green, yellow, and purple costume and a yellow cape in the same Kryptonian style that Jor-El and other Kryptonians wear.
The three brothers were collectively known as The Evil Three. Originally, U-Ban was a scientist on the Planet Krypton and was a member of Kryptonâ€™s ruling council, "which consisted of the ten leading scientists!". (S No. 65, Jul/Aug 1950)
However, unlike the other seven scientists they were evil and broke the Krypton Code of Honor. U-Ban and his evil brothers planned to conquer Krypton by building a horrifying machine that could â€œExtract all the moisture from the air making it unfit to breathe!â€ (S No. 65, Jul/Aug 1950)
Thankfully, the brilliant scientist and father of Superman, Jor-El found out of their evil plan and tried to stop them. Only to be captured by U-Ban and his brothers and tied up and The Evil Three used their machine on the people of Krypton and U-Ban demanded that they â€œAgree to overthrow the Krypton Council and declare and my brothers your rulers! Agree or die!â€ (S No. 65, Jul/Aug 1950)
The quick thinking Jor-El manage to free himself and using his scientific genius, converted the machine to release life-giving water into the air.
Jor-El got on the microphone and asked the people to hurry to the laboratory to get The Evil Three. Once there the Kryptonians [In this tale he refered to them as Kryptonites] wanted to kill U-Ban and his brothers, but the compassionate and noble Jor-El stopped them. Jor-El instead constructed a special transparent tube (a spaceship of sorts), placed U-Ban, and his brothers in it in a state of suspended animation and shot them into orbit around Krypton.
So when Krypton exploded, their tube-ship was unwitting sent off into interstellar space. There a meteorite crash into the tube-ship and awoke them from their trance.
Their tube-ship then crashed landed on Earth. There Superman met them for the first time and was astonished to find out they they had the same powers as he! So when Superman ask them how they have the same powers as himself, U-Ban replied:
"Super-powers? How amusing! Where I come from, everyone has see-through vision, extra-strength, and extra-speed!" (S No. 65, Jul/Aug 1950)
Later in the chronicles it was suggested that Kryptonians did not have any powers on Krypton and only gained super-powers identical to Superman under a yellow sun—see Superman, specifically section 6.1: Derivation of the Super-Powers.
They met Superman and retold their story to him. They also told him of their plan to conquer the Earth. U-Ban then used his amazing Ultra-Voice to shatter a tower, and Superman bravely flew to save the tower and repair the damage, which gave U-Ban and his brothers time to escape.
They later built a fantastic machine that hypnotized the people of Earth so that they could get the materials needed to make another version of their moisture extracting machine that they dubbed Project Z-2.
Superman, after noticing that the people of Earth were hypnotized, found that machine and destroyed it and confronted U-Ban, Mala, and Kizo. They agree to battle for the fate of the Earth itself but on one condition stated by Superman, that the battle take place where no human could get hurt.
â€œThus is arranged the most titanic battle of all timeâ€¦ A battle of Supermen!â€ (S No. 65, Jul/Aug 1950)
This sensational battle ended in a draw for not even Supermanâ€™s mighty muscles and super-powers could defeat The Evil Three all by himself! Later a trodden and bruised Superman decided to use his Super smarts to defeat them but tricking them into fighting each other with the use of his power of ventriloquism. Exhausted and unable to defend themselves, Superman took U-Ban, Mala, and Kizo away and created his own version of Jor-El's tube-ship and placed The Evil Three within once again in state of suspended animation and shot them into deep space.
U-Ban and his brothers returned to battle Superman again in July 1954 (Act No. 194 "The Outlaws from Krypton").