Time to give some praise to another specific Pokémon line. This time, something from Gen 1(!), but a little from Gen 6 as well.
I have always been a big fan of the Magikarp line. The whole concept of a weak, pathetic, useless fish which evolves into an aggressive, angry, terrifying dragon-like sea monster is amazing. I think they absolutely nailed the execution of the concept as well. I find their designs to be solid too.
I have said this before in another thread long ago, but I’ll say it here as well: I think Magikarp has one of the best models in the 3D games. It captures the essence of a weak, pathetic fish so perfectly. I don’t think any of its 2D sprites ever managed to capture it that well.
Training a Magikarp in any game is going to be painful as it can’t really do anything on its own and requires assistance from other Pokémon in order to grow. But once it reaches level 20 and evolves, Magikarp literally goes from zero to hero. It becomes a Gyarados, and the trainer who had the patience to train it gets rewarded with a very powerful Pokémon.
I like how Gyarados is practically a Dragon in everything except its typing. Its whole appearance just screams “Dragon!” yet it is not a Dragon-type, but a Water/Flying-type. When I was younger, I always thought it should be Water/Dragon, but as I have grown older, I have realized that I'm fine with it being Water/Flying. In terms of design, it doesn’t look very friendly or welcoming, but I think that’s good because that’s just a part of what it is. This is not a Pokémon you want to mess with, because if you do, it will end up making a mess of you! If you even survive, that is.
I have had great success with Gyarados in battles as well. It is a quite strong Physical Attacker with fairly good defenses as well as a great movepool with solid coverage. It also gets a great boosting move in Dragon Dance, which makes it stronger and helps to patch up its average Speed. Intimidate and Moxie are both great Abilities as well. The lack of a good Flying STAB is a little annoying, but it does get Bounce at least. Not the best Flying-type move, but I suppose it works. Personally, I found it to be is excellent as a Max Move when Gyarados is Dynamaxed. It was something I have made great use of in the Battle Tower in Sword. But I have had great success with Gyarados in other generations as well, notably Gen 5-7.
Gyarados has a really cool Mega Evolution too. It is not one of my top favorite Megas, but I still like it a lot. While the fact that it lacked a good Dark-type move at first was a little annoying, that quickly got fixed in OR/AS where it got Crunch. Like regular Gyarados, I have had great success with Mega Gyarados in Gen 6 & 7.
I also really like its typing, and its type change upon Mega Evolving. While it could be argued that it would be more logical for either regular Gyarados or Mega Gyarados (or both, for that matter) to be Water/Dragon, I have over the years realized how genius it was to make it go from Water/Flying to Water/Dark. It is really cool from a defensive standpoint as it changes how very many types affect it. Some are still unchanged, both regular and Mega Gyarados are resistant to Fire, Water and Steel, while they take neutral damage from Normal, Poison, Flying and Dragon. But the matchup changes for all other types. Let’s take a look at them:
Grass: Neutral -> Weak
Electric: 4x Weak -> 2x Weak
Rock: Weak -> Neutral
Fighting: Resisted -> Weak
Ice: Neutral -> Resisted
Ground: Immune -> Neutral
Psychic: Neutral -> Immune
Bug: Resisted -> Weak
Ghost: Neutral -> Resisted
Dark: Neutral -> Resisted
Fairy: Neutral -> Weak
11 out of 18 types affect regular Gyarados and Mega Gyarados differently. I think this is just awesome. Not sure about how it is in competitive, but I know from personal experience that in Battle Facilities, it means that choosing to not Mega Evolve Gyarados might sometimes be the better alternative. It all depends on what you are up against. I think it is genius and because of that, Mega Gyarados is my favorite Mega when it comes to type change, because of the type change it goes through upon Mega Evolving.