Generation VI of Pokémon has a bit of a reputation problem. The games, X & Y, are generally considered as the easiest of the main series. And while there's definitely an engaging plot and interesting lore to the Kalos region, after the sheer ambition of Generation V, X & Y felt a tad underwhelming.
Generation VI also introduced a lot less Pokémon than its predecessor, despite having one of the largest Pokédexes. Of the 76 Pokémon native to the Kalos region, only a few really stand out because of their sheer power, not counting Legendaries, Mythicals, or Mega Evolutions. However, they're so memorable that they immediately earn their place among Pokémon's fiercest and strongest.
Barbaracle
Barbaracle doesn't have one of the franchise's best designs. In fact, it's quite unappealing to the eye, a strange mix between a pile of rocks and a skinny man with way too many hands. A dual-type Rock/Water Pokémon, Barbaracle's assets rely entirely on its strong Physical stats, both over a hundred. With a base stat total of 600, Barbaracle ranks as one of Kalos' strongest creatures.
Its type combination isn't without its risks. It leaves Barbaracle with a four-times weakness to Grass, plus normal vulnerabilities to Fighting, Ground, and Electric. It is resistant to five types so that is something.
Hawlucha
The combination between a bird of prey and a Mexican luchador, Hawlucha is one of Kalos's greatest surprises. Unbelievably fast and shockingly strong, Hawlucha's then-unique Fighting/Flying-type made it a dangerous threat in battle. With a base stat total of 500, Hawlucha was powerful enough to be given a place among Kalos Champion Diantha's team.
Its dual-type carries a significant amount of risks, though. It has five weaknesses, one immunity, and four resistances. Overall a very balanced Pokémon, Hawlucha returned in both subsequent generations, proving its enduring popularity.
Pyroar
The only Fire/Normal Pokémon so far, Pyroar is said to be the companion of numerous Kings throughout history. Known as the Royal Pokémon, Pyroar has a base stat total of 507, aided by its high Special Attack and Speed. Both its Physical Attack and Special Defense are below-average, though, so that should keep things interesting.
Pyroar is weak to four types, is immune to one, and resists six, including the overpowered Fairy. It evolves from Litleo at the reasonable level of 36, making it a very strong Pokémon to have in a Kalos playthrough. Indeed, its fearsome appearance made it ideal to be a part of Lysandre's team.
Aegislash
By far one of Generation VI's best, most unforgettable, and useful Pokémon, Aegislash is one of the franchise's most daring and original concepts in years. A dual-type Steel/Ghost mon, Aegislash has the unique ability to change forms during battle, depending on the moves it's using. In its Blade Form, it has a massive 150 in both Attacks, Physical and Special. In its Shield Form, the opposite happens and the 150 goes to both Defenses. Both forms add up to a base stat total of 520.
The rest of its stats are all below average but that doesn't stop Aegislash from decimating more than one team. Weak to four types, Aegislash has three immunities and resists a staggering nine types. It was so strong that it received a significant nerf in Generation VIII, lowering its stat total to 500.
Aurorus
Aurorus is not only strong, it also has one of the most majestic designs in the entire franchise. Clearly based on a Sauropod, Aurorus also bears elements of the aurora borealis, which also inspires its name. With a seemingly excellent 521 base stat total, most of Aurorus's strengths rely on its high HP and Special stats.
The truth is, not everything is great when it comes to this splendid creature. Its dual-typing of Rock/Ice means it's weak to life itself. It has a whopping six weaknesses, including two four-times vulnerabilities to Grass and Steel. Furthermore, it only resists four types, meaning it isn't viable in battle. No other Pokémon has the same type combination as Aurorus, and thank God for that.
Tyrantrum
Tyrantrum is in a similar situation as its fellow fossil, Aurorus. It too is an impressive creature based on a dinosaur, capable of terrifying anyone who crosses its path. Tyrantrum also has a base stat total of 521, although nearly all its power is focused on both its Physical stats. Tyrantrum hits very hard but isn't the fastest, which means a lot of Pokémon can outspeed it.
Like Aurorus, Tyrantrum also has six weaknesses, although none is four-times effective. It also has five resistances, so everything pretty much evens out. Tyrantrum can be successfully used in battle, but always accompanied by a good strategy.
Chesnaught
The Grass Starter of the Kalos region, Chesnaught is a dual-type Grass/Fighting creature. This type is extremely tricky because it leaves Chesnaught with six weaknesses, including quad vulnerability to the Flying-type. It also boasts just as many resistances, so that is at least something.
Still, Chesnaught has a high base stat total of 530. Both Physical stats are its greatest assets, although its Speed is truly pitiful. Chesnaught's design is interesting, but compared to its fellow Starters, it truly got the short end of the stick.
Delphox
Kalos' Fire Starter, Delphox is a divisive Pokémon. On paper, the concept and design are amazing. Delphox seems to be based on a kitsune, a magical fox in Japanese folklore. Delphox even holds a fiery branch, probably a reference to a magic wand.
The interesting combination of Fire and Psychic further add appeal to this creature. Delphox's 534 base stat total is mainly focused on both Special stats and Speed. It can hit very hard and very fast, which sounds incredible. However, Delphox is incredibly frail and can easily fall to a wide range of attacks from any of its five weaknesses.
Noivern
Noivern is so cool that many often confuse it for a Pseudo-Legendary Pokémon, especially because Kalos's actual Pseudo, Goodra, is quite forgettable. A dual-type Dragon/Flying creature, Noivern is four-times weak to Ice and has three more vulnerabilities. However, it is immune to Ground and has five resistances, which provides a nice balance.
Noivern is also Kalos's strongest Pokémon without the need for an additional form. With a base stat total of 535, Noivern's Speed is truly spectacular. The rest of its stats are all above-average, with Special Attack as the standout. Noivern does have a setback, though, because it evolves from the far inferior Noibat at the high level of 48.
Greninja
One of the most popular Pokémon from later generations, Greninja's success is due in large part to its prominent role as one of Ash's Pokémon during the Kalos season of the Pokémon anime. Indeed, a Greninja with the Battle Bond ability can transform into a special form called Ash-Greninja, taking its already high 530 base stat total into an absurd 640, making it stronger than all Pseudo-Legendaries and even some Legendaries.
In both forms, Greninja's strengths rely on both Physical and Special Attack, and Speed, although it's severely lacking in both Defense departments. Its dual Water/Dark-type leaves it with five weaknesses, one immunity, and six resistances. Even without its additional form, Greninja is a dangerous weapon in battle and the strongest Pokémon in Kalos, by far.