History

Blast is the #1 S-ranked hero in the Hero Organization. His first appearance was when he effortlessly defeated Elder Centipede in one attack. Virtually everything about him is unknown. The only person who has seen Blast is Terrible Tornado. Although his powers are unclear, he is one of only two people to exceed their limiter, the other being Saitama. It has been stated that Blast could beat all the S-ranked heroes at once, and is possibly near Saitama’s level.
He was first seen as a flashback in the manga (18 years prior to the start of the OPM timeline) after he had saved Tatsumaki from a monster, in which he asked her soon after why she didn’t use her powers to protect herself and she dishonestly answered that they were not working. He then tapped into her mind and found out about her sister, Fubuki and advised her to use her powers more to protect others.
Blast since then had been mentioned a few times like in the S-Class meeting in which they acknowledged his absence and state that his current whereabouts were unknown.

In another Hero association meeting, he is mentioned by a staff member who acknowledged and is frustrated with his long absence. Sitch then states that he has faith that Blast will return one day once a big enough threat rises (God-level).
Drive Knight also asks whether or not Blast will come if the HA HQ were to be attacked, in which Sekingar replies that Blast is more or less retired so it is unlikely.
Sweet Mask has a mental breakdown and suddenly has a vision with Blast in it. He tells him ‘It’s fine now’, he also sees a dead monster beside him.
During the monster association raid, Saitama frees Flashy Flash‘s arm from an oddly heavy cube which he drops and it sinks into the ground, Manako (as well as Flash) could not lift it.

Blast suddenly appears out of a Black-Hole portal after God speaks to them due to contact with the cube. He then informs them of why he is here and asks them if they ‘accepted the deal yet’. He also proceeds to ask Flashy Flash why he is ‘far below the ground’, Flash tries to turn the question on him and then tries to test him by attacking him with the ‘Flashy kick’ at maximum speed. Of course, he is too fast for Flash as he easily dodges his kicks then appears behind him in an instant as he is a ‘statue’ in his perspective due to his sheer speed. He then tells them about how time flows slower in this space than the real dimension outside and offers to take them back via his portals. Before teleporting them, he questions why they have a monster with them which is not a prisoner, soon after, he tells them to send his regards to Tatsumaki and Sitch, then clashes his fists together and makes the portal.
He has not been seen since but something to note is that he has a son called Blue in the webcomic.
Appearance

Blast is a tall man of muscular build, with spiky, graying hair and a slight beard. He wears bulky armor with large shoulder pads, a large cape worn out at the bottom, and emblems of his name on his chest and the backs of his shoes. His gloves have circles on the back of his fists, which form an infinity symbol when he presses them together to teleport. His suit has mild damage, presumably sustained from his many battles. He also wears shades and has a scar running across his face between his eyes. The outline of his iris is a wavy black pattern, as opposed to just a consistent outline seen in other characters.
In the past, Blast’s appearance was largely similar to today, but he looked younger, with darker hair and no beard. Additionally, neither his armor nor himself had sustained damage or injuries, and he did not wear shades.
Personality
Blast does not disclose his personal information in the Hero Association Catalog. However; akin to Saitama, he considers his hero work as just a hobby. He also seems to have independent tendencies, keeping his location and status unknown, and advising Tatsumaki to use her own powers to defend herself rather than expecting others to save her.
In the present, Blast has a casual and easygoing attitude as he did not seem to be very bothered by Saitama, Flashy Flash, and Manako touching the cube since they didn’t know what it was nor did they accept the deal, and he was willing to explain what the cube was. Blast was also not angered by the fact that Flashy Flash tried to attack him, simply telling him to calm down, and he was willing to teleport all of them out of the area they were in. Blast did not question the presence of Saitama with an S-Class hero and even answered Saitama’s question about him warping there; however, he became momentarily serious with the presence of Manako with them since she is a monster. After Saitama’s explanation, he quickly went back to his easygoing attitude and accepted the explanation with no further questions.
Blast seems to not be completely out of touch with other heroes, as he recognized Flashy Flash and knew his exact ranking. He also requested Flashy Flash and Saitama to send Sitch and Tatsumaki his regards.
Powers & Abilities
Superhuman speed & reflexes- One of his abilities is possessing immense speed, he is capable of making Flashy Flash look like a complete statue due to his perception speed only and is too fast for his eyes to register.
Super strength- Blast also possesses superhuman strength to a degree that he can twirl around the mysterious cube, which Flashy Flash couldn’t lift up in which it sunk into the ground after Saitama tossed it away, and also bring the massive city-sized Elder Centipede to the brink of death with ease. It also seems like he made a massive hole in a giant monster when saving Tatsumaki with relative ease, similar to the damage Saitama did to Deep Sea King.
Dimensional manipulation/teleportation- Blast has the ability to open up Black-Hole looking portals by punching his fists together in which an ? symbol appears, it allows him to transfer him and others through space-time.
Psychic ability- It seems Blast has some form of psychic powers as, in one instance, he places his hand on a younger Tatsumaki‘s head and sees a vision of Fubuki, her sister. Fubuki also once stated that he is also an esper, like her and her sister.
Laser eyes/blast power- It is stated, by Fubuki, in a handbook that Blast has the ability to shoot powerful laser beams from his eyes.
Gadgets/technopathy- Fubuki also stated, in the same handbook, that he has the ability to command and control trillions of robots.
Mysterious Cubes

The Mysterious Cubes are a series of cuboid objects that are used to communicate with God.
According to Blast, the cubes act as a transmitter that distort space and allow for communication with God. Anyone who comes in contact with a cube is able to hear the voice of God in their head.
One of the cubes was first seen 18 years ago during a flashback of Tatsumaki when she was saved by Blast from a hybrid monster. Another cube was also found by Saitama, Manako, and Flashy Flash in the rubble of the Monster Association Headquarters. Blast stated that there are multiple cubes scattered around the world, and that he has been collecting them as a hobby.
The cubes appear to be extremely heavy, as one was able to get Flashy Flash’s arm stuck, and sunk into solid rock after being dropped by Saitama. Additionally, Manako was unable to lift it back up.
History
One of the cubes appears for the first time during Tatsumaki’s flashback as she recalls the events of 18 years ago when she was saved by Blast from a monster. It is revealed that Blast was holding a black cube when having a conversation with Tatsumaki at the time.

Later, when Saitama and Manako are helping free Flashy Flash, they come across another cube which had pinned Flashy Flash’s arm down. Saitama inspects it before throwing it away without having any idea what it actually is. As Tatsumaki begins to lift the remains of Monster Association Headquarters into the air, Saitama along with Flashy Flash and Manako peer out into the hole expecting to see the underground, only to instead be greeted by a black void, with a mysterious figure sitting prone inside, though the three cannot see it.
God’s voice begins to speak in their heads, saying that if they touch the cube and make a wish, the being will either grant them power, or they will “be confiscated.” Immediately afterward, Blast appears and is relieved to find that the group did not accept God’s words. He takes the cube, transferring it through a portal to an unknown location.
Other media
Anime

Blast is yet to appear in the One Punch Man anime and has only been mentioned a few times, one episode showing a silhouette of him.