Board Thread:General Discussion/@comment-117.226.132.134-20170507151359/@comment-50.115.70.242-20180119225053

105.105.44.229 wrote: The Only person who has witnessed Blast (that we know of) is Tatsumaki when she was a kid. Other than that, he isnt talked about at all by the HA or anyone else in the S class other than child emperor. In short, the only confirmed person to have even seen Blast, is Tatsumaki.

Considering the circumstances of Blast's appearance during Tatsumaki's flashbacks... it is likely that that he was imagined by Tatsumaki to create a goal that she could strive for. To be a hero that doesn't have to rely on anyone. Blast is the idealized hero that exists in Tatsumaki's mind and nothing more.

After she joined the HA, Tatusmaki requested to put Blast in the Rank 1 in S class, something that the HA couldn't refuse considering her unquestionable authority as a powerful hero.

Look at the manga... you see him and saitama defeat elder centipede