Vaporeon's reign of terror has ended in Pokemon Go.
Yesterday, Pokemon Go updated several Pokemon's movesets as part of their big "Gen 3" reshuffle. While most players' attention was focused on the 50 new Pokemon added to the game, there was also a potentially big change to the metagame, as Gyarados was transformed into a viable Water-Type attacker.
Since Pokemon Go came out in 2016, Vaporeon has dominated gyms due to its high Attack and Stamina stats, its effectiveness against certain types of "bulky" Pokemon, and its relatively cheap cost to obtain in the game. While there are a few Water-Type Pokemon with stronger Attack stats, none could really match Vaporeon's lasting power and high CP, which is why Vaporeon remains a viable defending option to this day.
Vaporeon's domination in the metagame was particularly frustrating to fans of Gyarados, which has significantly higher Attack and Defense stats. In theory, Gyarados should be superior to Vaporeon, but its lack of a Water-Type fast move meant that its effectiveness was sorely limited. That extra STAB (same type attack bonus) from firing off dozens of fast attacks adds up over the course of a battle, and Gyarados simply couldn't compete with Vaporeon when it came to Water-Type attacking.
However, the new update also introduced a new Water-Type fast move, Waterfall, which is stronger than Vaporeon's Water Gun attack. While Water Gun does 12.5 damage per second, Waterfall does a whopping 16.67 damage per second, which gives it a big advantage over the course of a minute long battle. For context, Waterfall does about 250 more damage than Water Gun does over the course of a minute, which is the equivalent to nearly two extra Hydro Pump attacks.
Pokemon Go modified Gyarados's moveset so that it can learn Waterfall as a fast attack, but Vaporeon is still stuck with Water Gun as its only potential fast attack. This means that Gyarados is now a better Water-Type attacker than Vaporeon. And any player who has a Gyarados can use a Fast TM to potentially upgrade Gyarados's moveset.
Of course, since it takes 400 Magikarp Candies to get a Gyarados, many Pokemon Go trainers will probably stick with Vaporeon when planning a Water-Type attack. And Gyarados won't have very long at the top of the Water-Type pyramid. After all, the Legendary Pokemon Kyogre is on the way, and it knows both Waterfall and Hydro Pump (the ideal moveset for Water-Type attackers.) Still, Pokemon Go players can celebrate for a much needed shakeup in the metagame. Now things are getting really interesting.