Lord Boros

"This state... It burdens my body immensely, similar to anaerobic exercise. It's supposed to be a trump card I only use to settle a fight quickly, but this man... makes me wanna go all out."

- Boros to Saitama after releasing his full power

Lord Boros is a major villain from the webcomic, manga and anime series "One Punch Man". He is the leader of the Dark Matter Thieves, a group of aliens who invade other planets. Boros's personal goal is to find an opponent who is worthy of his might, so he traveled to planet Earth to fight Saitama.

Appearance
Lord Boros is a slim, cyclopean alien with lightly colored spiky hair and pointed ears, which are adorned with multiple earrings. His face is covered with crack-shaped markings that start from his eye(and cover most of his body presumably). In the area of his body below his chest, there seems to be another eye, which moves in synced with his original one. At first, he is seen wearing a full body armor that suppresses his powers. When the armor is broken by Saitama's punch, he attains a more intimidating and slightly more muscular build, while his skin darkens in color, parts of his body grow scales and spikes, and his markings start emitting energy, and gain a lighter color. In his Meteoric Burst form, his appearance changes drastically. His hair grow reaching his back, his eye's sclera becomes black, and his body becomes engulfed in energy, while his markings now return to their original, dark color, and right before he fires his Collapsing Star Roaring Cannon his body briefly turns black and yellow

Story
Boros hails from a planet with harsh living conditions, which gave the members of his race unprecedented strength. Boros rose among them as the best one, growing so strong that practically nobody could match him. He eventually grew bored, deciding to turn to galactic conquest and creating the Dark Matter Thieves, traveling the space to find an opponent who could give him the fight he desired. During his travels, he met with a fortune teller who told him he would find a very strong opponent on the distant planet Earth. Though his crewmates distrusted the prophecy, Boros still followed it, and after 20 years they finally arrived at Earth. Their ship hovers about A-City, which is wiped out in an instant by their cannons. Boros awaits at his throne at first, but after hearing explosions inside the ship he goes to the control room, where Geluganshp informs him of a intruder that invaded the ship and was killing their forces. Boros tells him to team up with Groribas and Melzalgald, but Geluganshp informs that Groribas was defeated already. Boros returns to his throne and patiently awaits for the intruder. After defeating Geluganshp, Saitama finally reaches Boros, who congratulates him and tells his story, but Saitama punches him, telling him that boredom was a stupid excuse for attacking other's planets. Boros survives the punch, which breaks his armor. Claiming it was only a power limiter, Boros unleashes his power and the two warriors fight. After losing one arm, Boros unleashes his Meteoric Burst form, continuously attacking Saitama and kicking him with enough strength to send him to the moon. Saitama returns and uses his Normal Chain Punches, which pulverize Boros though he recovers almost instantly. Impressed, Boros launches his final attack, the Collapsing Star Roaring Cannon, which was a huge beam of energy strong enough to wipe the entire planet's surface. Saitama counters the attack with his Serious Series Punch, which repels Boros attack and critically wounds him. With no energy left, Boros compliments Saitama, who tells him it was a good fight. However, Boros calls him a liar, for he realized Saitama was holding back all the time and that he was no match for him, dying shortly after.