The Flash is definitely from DC Comics. DC has developed a rich and complex storyline around him over the years. He's got his own unique powers and adventures within the DC framework.
The Flash is definitely a DC Comics character. DC has built a rich story and universe around him. He's got super speed and is a key figure in many DC storylines.
I'm not entirely sure if it's a widely popular concept, but it does have its charm. Combining the high - tech world of Tony Stark with the super - speed abilities of Flash can lead to some really exciting and unexpected storylines. For example, Flash could use his speed to help Tony in his lab work, or Tony could develop some new technology to enhance Flash's powers. However, it also depends on how well the fanfiction is promoted and received within the fan community.