According to the show’s Fandom page, Blindspot’s character is clearly influenced by Daredevil, a character from the Marvel comics. In Daredevil’s origin story, he becomes blind after an unlucky encounter with radiation. But in losing his sight, he gains other super human abilities, being able to sense people with his heightened hearing and touch. This is called his “radar sense.”
Blindspot’s origin story is very similar to Daredevil’s, and his abilities are almost identical.
Blindspot is brought to the group by Ashley, who believes that having a superhero with a disability could be good PR for the group. As he’s blind (hence the name Blindspot), he has a heightened ability to hear and superhuman agility.
Ashley brings Blindspot to the Seven, believing that he could be good for the group, though Homelander quickly crushes that idea. While Blindspot is able to identify that Homelander is in the room, without him having spoken or made his presence clear, he’s unimpressed.
Within minutes, Homelander reduces Blindspot to a puddle on the floor after bashing his ears in, thus rendering him unable to use his superhuman hearing. According to the Fandom page, he calls the hero a “cripple,” stating that he would not be an asset to the team.
Blindspot is considered a minor character in the show, making a brief appearance in Season 2.