Xi'ga E'shan is a former Commander of the Space Pirates. He unofficially relinquished his command shortly before the events of Metroid Prime 3: Corruption, with most if not all of his troops remaining in his command.
E'shan, was most infamous for his remarkable skills in melee combat, even refusing to carry with him a beam weapon of any kind. His obvious preference being a wrist-mounted plasma blade. Aside from his greater combat skills, his troops were all trained as such, to be ultimate warriors, and to eliminate threats with ease. E'shan also held a sort of "code of honor" on the battlefield. Though ruthless and frighteningly efficient, when taking part in a duel, E'shan refused to strike an unarmed, or downed opponent, as he saw this as a cowardice tactic. Though this "code" was only reserved for a single, one-on-one duel, a fight to show skill and prowess. In any other case, E'shan would simply kill, with no intent of honor. E'shan's reasons for leaving his brethren, and it's cause, was due to his disagreements with the use of Phazon as a battle enhancement. He found it ridiculous and dishonorable to artificially enhance oneself for the purpose of combat efficiency. This included the use of Phazon with Metroids. He soon found himself at irrefutable odds with his brothers, and left. Hoping to find another, more natural, alternative to the battle enhancement of Metroids.