T'Mar Veomin (Trandoshan/Zabrak Hybrid) was a half-brother to Darth Maul having the same mother, mother Talzin. His mother was captured by a Trandoshan mercenary named Jeruuk Veomin when she was a young woman and impregnated her. Jeruuk kept her inside a pod that kept her unconscious, and sustained throughout her pregnancy until it was time for her to give birth. He had a surgical droid remove her baby then sold her to other mercenaries who planned to eat her as rations for an extended mission to the outer rim systems. Jeruuk took his son to Korriban where he set-up a temporary residence while he learned the Sith teachings from a holocron he found on one of his missions.
T'Mar became a powerful warrior over the years as he grew to adulthood and left Korriban after finding an ancient Sith technological braclet that was able to open up a portal to the world between worlds.
He activated his new device and walked through it. he was surrounded by portals to different time-lines to various locations in the past, present and future. He saw his father attacking a young Zabrak woman at a time where he realized that she was his mother. T'Mar saw a much older version of his mother talking to two Zabrak men as she referred to as her sons and also saw one of those brothers being cut in half by a Jedi. He decided to go through that window but after it was clear of everyone who was there.
He took a Nemoidian fighter ship and went to the Jedi Temple to get revenge for his brother. However, he encountered Master Yoda who managed to get through his rage and talked him into learning about the Jedi ways because he felt something good in his heart.
He became a Jedi Knight by the time the Clone Wars broke out and was put in command of a strike-team he renamed: Venom Squad. T'Mar found out that his brother he thought died 10 years prior was named Darth Maul who was still alive.