Warning: The following article contains spoilers for the second season of The Flash. Do not read this unless you've watched the entire season, or unless you don't care and are bored.
Holy wow, what an incredible season!! The Flash really has improved upon itself from the first time around. We've seen a lot of spectacular aspects. New enemies debut. The characters become more fleshed out. Also, we see that the writers really respect the source material. Well, let's speed onwards to the review! (Okay, bad joke!)
One of the spectacular aspects of The Flash's second season is that we see more of his rouges. Since a whole lot of them appear, I will just mention my favorite ones.
For example the monster, King Shark finally makes his screen debut. He travels from Earth-2 to kill Barry because Zoom commanded him. (I'll get to Zoom in a little bit.) King Shark is a humanoid shark that is mostly famous for being a part of the Suicide Squad. (But he's not going to be featured in Suicide Squad.) He is immensely strong, a skilled swimmer, and can survive underwater or on land. The second time he appears, he tries to kill Wally West to lure in Barry. While King Shark was underwater, Barry created a tornado by running to generate electricity. King Shark is then subdued, and is taken into custody.
Also in season two, our heroes run into Killer Frost. Killer Frost is the alternate version of Caitlin Snow on Earth-2. She is a meta human who controls the power of ice. (Basically, think of her like a female Mr. Freeze.) While on Earth-2, Barry and Cisco try to rescue Harrison Well's (Earth-2) daughter from Zoom. Killer Frost gets in the way along with Reverb, the alternate persona of Cisco. What happens then is, they try to kill Barry which Zoom doesn't want. So, Zoom slaughters them both.
And lastly the main villain of The Flash's second season is Zoom. Zoom is a speedster like Barry but evil. With his mask on, Zoom has a dark and intimidating voice. He runs with blue lightning, and basically has the same exact abilities as Barry. Zoom is capable of throwing lightning, making speed mirages, and easily can tap into the Speedforce. Throughout the first half of the season, Zoom masquerades himself as Jay Garrick. He wore Jay's iconic helmet, and tricks Barry into trusting him. When the fake Jay Garrick was supposedly killed by Zoom, the helmet is left behind. And when Cisco touches it, he learns that Jay was really Zoom the whole time. On Earth-2, Zoom used to be a man named Hunter Zolomon. He was a deranged serial killer who became a speedster when the Earth-2 particle accelerator exploded. In the end, Zoom is caught by the wraiths of the Speedforce, and decays. (In the comic books, he is now known as Black Flash.)
Another great aspect of The Flash's second season is that some characters become more fleshed out (while some don't).
Take Barry for instance. In season two, Barry becomes a much faster and more mature speedster. He learns to throw lightning, and masterfully taps into the Speedforce with much more ease. While trying to maintain his sense of humor, Barry takes more seriously the role of being The Flash. We see him inspire Wally West to clean up his life, and make things right with his father. Barry becomes close to Patty Spivot, only to have his secret identity being revealed. Barry rescues the real Jay Garrick, which turns out to be the Earth-2 version of his father. Also, Barry contemplates becoming romantically involved with Iris. Despite the fact, he is still hellbent on going back in time to save his mother from the Reverse Flash.
Cisco becomes more fleshed out this season, since we learned that he's actually a meta human as well. We get the privilege to see Cisco get closer to becoming his super alter ego, Vibe. Basically, what he can do is touch random objects and people to see visions of dangerous current or upcoming events. Cisco can also push away objects like how a Jedi can push with the Force. And with his powers, Cisco can open up entrances to Earth-2. Fortunately, Cisco still is the lovable movie referencing geek we met in the first season.
Iris West is more serious this time around. And this is more personal for me to say. Because honestly, I felt that Iris was incredibly annoying in season one. I don't really know why I feel this way, but I really kept wanting her to shut up. But this time, Iris is more (in my biased opinion) more competent. She is constantly prepared to assist The Flash take down Zoom and his minions.
Unfortunately, not all of the characters become more fleshed out in season two. Joe is still the same. Caitlin is basically unchanged because she lost Ronnie in season one, and was duped by Zoom into losing Jay Garrick as a love interest. Ultimately, Caitlin is unfortunately pretty static. Earth-2 Harrison Wells doesn't really count either. Both versions of Dr. Wells are basically arrogant jerks.
One last great aspect of season two is the fact of the writers respecting the source material. A lot of what happens is fairly accurate to the comic books. Whether it's Barry learning to throw lightning, or Wally West being exposed to the particle accelerator reattempt. This strongly suggests that we will see him become the next speedster alongside Barry. It's very apparent that the writers really care about what this show is supposed to be. Take also for instance, the fact that Jay Garrick's costume is accurate. He has a giant lightning bolt on his costume, and he possesses the iconic helmet from the original comic books. And finally how everyone in Central City believes that The Flash is a hero. (Cisco made a Flash signal, saying he got the idea from a comic book.)
All in all, The Flash's second season was a blast!! A lot of great aspects occurred. We got to see more of Barry's rogue gallery. A few characters were more fleshed out. And finally, we see that the writers actually respect the source material. Honestly, I'm worried that all of these events will be undone since Barry saved his mother from the Reverse Flash, which would alter the timeline. However, this season was amazing and I can't wait for Barry to return in October! A +