Before I forget, the last episode of The Flash also gave us a nice Easter-egg that, if not exactly a new character, represents a nice nod to the comics. In The Flash Reborn, in fact, since Barry Allen proves to be too confused to face the Samuroid as he’s been challenged to do, Wally tries to take his place, and for the first time ever he suits up as The Flash. Albeit he’s easily defeated by the Samuroid, who demands “the real Flash”, his appearance is quite a sweet gift for the comicbook readers, as Wally eventually becomes The Flash, and even surpasses his mentor. Let’s see together.
Life for Kid Flash hadn’t been exactly easy, as going through adolescence had exacted quite a toll in his superhero career: being struck by a lightning as a kid and not as an adult like his mentor Barry Allen, his body reacted differently to the Speed Force, and when his organism started to change due to puberty, everytime he used his super speed he was affected by an incredible pain. For a while he had to stop being a superhero, and he dismissed his Kid Flash identity. 
During the cosmic and multi-dimensional war between the Monitor and the Anti-Monitor, however, Flash sacrificed his life to destroy the enemy’s Antimatter Cannon, dissolving into thin air. At the same time, Wally himself was hit by a ray of anti-matter at full force, and he barely survived. As a consequence of his battle injury, Wally’s speed was reduced to “merely” the one of sound, but it also had another unexpected side-effect, as it cured him of his illness, freeing him from the pain. As the universe was saved, Wally became convinced that Barry was actually still alive, and that he would have come back eventually. To “keep his place” in Central City, Wally decided to don his mentor’s mantle in his absence, becoming the new Flash. He never hid his intention of keeping this role temporary, of course, but Central City’s population didn’t exactly appreciated this, nor his awkward attempt to take the hero’s place. Things became even worse when the new Flash was publicly humiliated by Doctor Alchemy: Wally was saved only by Green Lantern‘s intervention, and the space hero announced that he would have protected Central City’s in his fallen friend’s place. Disheartened and saddened, Wally gave up his ambition of being The Flash, and renounced to be a superhero once more… at least until Alchemy came back, this time besting both Green Lantern and Jay Garrick. Despite Wally’s faith, no Flash came to save them. In that very moment, he realized Barry was truly gone.
To save his friends, Wally donned the red costume once again, and this time, knowing that everything depended on him rather than on the deceased Barry, he defeated Alchemy, making his true, official debut as the new Flash. From that moment, however, he felt that the role of Flash, that he meant to be only a temporary solution, was kind of imposed to him: angered for this new situation, and for the irrational feeling of being abandoned, Wally became 
quite childish and immature, something that affected his private life greatly. After winning a lot of money in the lottery, he bought a huge villa in Long Island, and moved there with his girlfriend, Frances Kane. When she dumped him, he immediately moved in with a new one, the model Connie Noleski, and later the not-yet divorced Tina McGee, who was also older than him (something that created some tension between her and his mother Mary, who also lived in his house). Then, as fast as it had arrived, all his fortune left: Wally lost his money on the stock market, had to leave his house and to move to a small apartment in Brooklyn, and Tina left him. The top of misfortune arrived when the alien Durlans robbed him of his speed, taking away the last thing in his life he truly cared for. Jerry McGee and Tina helped him in regaining it through chemicals, but Wally obtained even more than he asked for, and became too fast to control himself, eventually turning into some sort of speed monster. Again, his friends Chester “Chunk” Runk and Mason Trollbridge were the ones who helped him to regain control, becoming The Flash once again. It was clear, however, that Wally needed a mentor and a guidance, and he found both in Golden Age Flash Jay Garrick and in his wife Joan: following their invitation, he moved to their place, in Keystone City, where the seasoned Flash started tutoring him, making him truly worthy of filling Barry’s boots. He also found emotional stability in a relationship with Linda Park, a reporter he truly fell in love with. It was time, finally, that he dropped the “Kid” out of “Flash”.
Wally West is a young man who suddenly found himself wearing shoes too big to fill, replacing a friend and a mentor he wasn’t really ready to say goodbye to; after a period of “extended childhood”, however, Wally is now a mature and responsible hero, fully aware of the responsibility his role demands of him. As The Flash, he’s among the fastest beings ever existed, having proved sometimes even to surpass his mentor, Barry Allen, the one thought to be the fastest Flash ever; his connection to the Speed Force grants him an unimaginable speed, as well as superhuman agility and reflexes, enhanced strength and senses, the ability to create small tornadoes by swirling his arms, to phase through solid objects, to move on vertical surfaces, to travel through time and dimensions, to fly like a helicopter by spinning in the air, and much more; he also developed a personal fighting style matching his speed, the apex of which is his Infinite Mass Punch, a blow that focuses his near-speed of light into a single punch with the energy of a white dwarf star. So fast that he can’t use his full powers on the planet without destroying it, the new Flash is a young hero who’s still testing the extent of a seemingly limitless potential, of the greatest defenders humanity ever had.
Who's Who 