Wally West is a popular character, and to many, the best incarnation of the Flash. CW's Flash TV Series has been on a great run so far. And I think it would be awesome if they did introduce Wally West. Keep in mind, I know that there is the posibility Ezra Miller may be playing Wally in the movies, so it's unlikely. Let it also be known, we aren't here to talk about his, or Grant Gustin's abilities to act. That being said, let's begin.
So, the thing is, we must make Wally older. In the comics, Wally was about 10 when he first got his powers. CW is directed towards Young Adults/Teens. So since Barry himself is about 25/26, I think 18 would be a great age for Wally. It allows for him to be mature, but younger than Roy/Thea, so if they were ever to team up, it would be a little more interesting since he's three younger, making the age gap a thing. Now, while on the topic of Roy Harper, we cannot redo his backstory. So, no, Wally is not going to be some young punk kid that grew up in the ghetto and is very street smart. Instead, I see Wally as growing up almost as a younger brother to Barry. He could be adopted by Joe's brother/sister/whatever, after his parents left him/died/whatever, just like Barry. However, instead of delving into the impossible, Wally kept it all bottled up inside, and instead deflected with humor.
His humor is going to be a thing. Just like Barry, he was bullied. However, he would taunt his bullies, making jokes and such, getting into multiple fights that he would run away from. But, his big mouth won't allow him to stop, so even at 18, he still gets into fights. He would be attending college, which would explain why we haven't seen him yet. He comes to visit Barry and Iris (in say, the midseason finale), and while there, he learns of the Flash, immediately feeling a connection to him. And, through a series of coincidences, he stumbles upon a hostage situation.
Here, let me just say, I hate Wally's backstory in the comics. It is perhaps the biggest coincidence in all of comics, and that is saying something. He's in Barry's lab, with Barry as "The Flash", and says "Gee, I wish I could get struck by lightning as well" and Barry says "Haha, well you know what they say, lightning never strikes twice". Then, it strikes again! So in the TV show, I say a new back story is necessary, and I would say, it's quite interesting.
So, again, he's in this hostage situation, where he just keeps running his mouth, saying things like "The Flash is coming, and when he does!" A gun is pointed at his head. Barry comes in, takes out all the bad guys, but Wally ends up getting shot. So, seeing limited options, Barry transfuses some of his blood to Wally so that Wally can heal himself. That, along with a blast from a defibulator (acting as the lightning) gives Wally his powers, which he doesn't know about, until he goes back to school...
Barry doesn't know if he gave Wally powers or not, so instead opts to just keep a close eye on him. While on campus, trying to evade some thugs he had previously mocked, he discovers his powers. So he decides to try and train himself, without Barry's knowledge. He eventually makes a very simple suit for himself, using the colors blue and white to differentiate himself from Barry, and begins to take out petty crimes. Once Barry finds out, he approaches Wally, who is still unaware that Barry is the Flash. It is here that Wally somewhat becomes the Season's Main antagonist of sorts, as he is scared of what Barry may or may not do, so he lashes against him. And Barry, scared that Wally may become like Harrison Wells/aka Reverse Flash/aka Eobard Thawne/aka whoever he actually is, decides to use whatever force is neccessary to keep Wally in check.
Wally soon takes up the name of Impulse, which was originally taken up by Bart Allen in the comics, and continues to fight on against the Flash, eventually becoming faster and beating him, forcing Barry to reveal himself by the season finale. Throughout the season, Barry was very hesitant about telling Wally, because he doesn't know what Wally would do. So that is a pretty big step. And seeing as now he knows that Barry wouldn't do anything to hurt him, and surrenders to him, and goes to Star Labs for observation.
The season then ends with Barry and Wally taking on a team of sorts, with Wally getting a new suit designed by Cisco and (potentially if she hasn't turned batshit insane yet) Caitlyn, officially becoming Impulse.
So, there's my idea. It's original, that's for sure. But, I think it respects the comics, and puts a new spin on the story. Thoughts? Comment below! And thank you for reading!