In The Flash season 2, when Prof. Wells was trying to recreate conditions of a particle accelerator explosion to restore Flash’s powers, accidently Wally and Jesse got exposed to the dark matter radiation. But they didn’t immediately become a speedster, which puzzled all of us. It was only a matter of time before someone is transformed into a speedster, we saw Wally West as the speedster fighting “the Rival” in the Flashpoint timeline.
In DC comics, he was born to Rudolf and Mary West. He was always looked down upon by his parents, bullied by his brother. He is the successor to Barry Allen. He was given Flash costume by Barry, who trained him and took him under his wing as “Kid Flash”, the show-makers have used it in the TV show as well although he doesn’t like being called as Kid Flash.
The biggest question on everyone’s mind is – How will he actually become Kid Flash in the present timeline? But as Jay Garrick (Henry Allen’s doppelganger on Earth-2) told Barry Allen that you can’t really fix everything just like if you piece together a broken cup, it will not be perfect. When Barry Allen came back to the present timeline, much hasn’t changed but several things are different. For instance, Wally West isn’t a speedster now, he is just a kid who loves engineering.
We saw ‘the Rival’ or Edward Clariss (he is Kid Flash’s nemesis in comics) fighting both Barry Allen & Kid Flash during the Flashpoint, in the end, he lost his speed for good. Consequently, Barry went back in time with the Reverse Flash/Eobard Thawne and allowed him to kill his mother to fix the timeline. Despite that ‘the Rival’ reappeared as his powers were re-activated by Dr. Alchemy. When he failed again, Dr. Alchemy created a new Meta-human known as Magenta who can control metal. In both the cases, the common link is Dr. Alchemy who is restoring powers of people who had them during Flashpoint. It’s only a matter of time for Wally west to start having dreams of Dr. Alchemy offering him to regain his speed powers and turn against Team Flash.