Pokémon has recently faced a steep decline in difficulty. These games used to be hard. Gym leaders would stomp unprepared trainers into the ground. They were essentially walls blocking progress and ensuring only the strong could continue. Taking them on and winning had real meaning — it was satisfying.

Modern gym leaders rarely pose any real challenge. It's usually easy to defeat them in one attempt, without needing to invent any new strategies. With that in mind, we took a look back at some of the hardest bosses from the Pokémon series, and the tactics used to defeat them. Should Pokémon start including these sorts of tough bosses again?

10 10/10 Brock (Kanto)

Brock from Pokémon standing against an arena backdrop.

Brock is ranked low because he can be either very easy or very difficult depending on the player's choice of starter Pokémon. Getting over him can be very rough; he's Pokémon's rock wall.

Brock uses only Rock/Ground type Pokémon: Geodude and Onyx. Due to the Rock type's resistance to both Normal and Fire damage, Charmander is a bad option. Also, Ground completely resists Electric, so Pikachu is out. The difficulty is made worse by the lack of other Pokémon at this stage in the game; Rattata and Pidgey just won't be much help. Mankey is a good option, however, they only appear in Pokémon Yellow.

9 9/10 Tate & Liza (Hoenn)

Tate and Liza from Pokémon standing against an arena backdrop.

Pokémon Emerald introduced the series' first gym leaders that can only be taken on in a double battle: Tate & Liza. These Psychic-type gym leaders have four Pokémon between them: Xatu, Claydol, Solrock, and Lunatone. Their Pokémon have good type coverage. Plus, Solrock has Sunny Day and SolarBeam, which is an excellent combination. Furthermore, all of their Pokémon are above level 40, which is amazing at this stage of the game!

Tate & Liza are especially difficult because double battles tend to spiral out of control. They give the player less time to react, and multi-hit moves like Earthquake and Surf become especially deadly. However, Tate & Liza still pale in comparison to some of Pokémon's truly difficult foes.

8 8/10 Whitney (Johto)

Whitney from Pokémon standing against an arena backdrop.

Whitney is arguably the most notorious gym leader of all time thanks to her Miltank and its move Rollout. Her early placement as the third gym leader makes her Johto's first real roadblock. With Rollout, her Miltank does progressively more damage each turn. Unless it can be quickly defeated, Whitney is liable to wipe out her foe's entire team in a matter of moments.

Whitney is often cited as one of the absolute hardest gym leaders of all time. While she is indeed difficult, there are multiple ways to counter her, hence her relatively low ranking. Drowzee is a good counter for Miltank, as is any Pokémon that can inflict paralysis or confusion. These status ailments can cancel Miltank's Rollout, forcing it to restart and more or less negating the threat.

7 7/10 Morty (Johto)

Morty from Pokémon standing against an arena backdrop.

Morty is the fourth gym leader from Gold, Silver, and Crystal. He doesn't typically cause much trouble in the original games, but in the Fourth Generation remakes (HeartGold and SoulSilver) he can be quite tough. He has the same team in both games: two Gastlys, a Haunter, and a Gengar.

In Generation Four, all of Morty's Pokémon have the ability Levitate. This means they negate Ground-type moves, which would ordinarily destroy them thanks to their Poison typing. They're all still vulnerable to Psychic moves. However, Gengar and Haunter will quickly knock out Psychic Pokémon with Shadow Ball and Night Shade, respectively. Due to a lack of reliable counters (especially in Generation Four) Morty is tougher than the notorious Whitney.

6 6/10 Fantina (Sinnoh)

Fantina from Pokémon standing against an arena backdrop.

Fantina is a Ghost-type gym leader from Pokemon Diamond, Pearl, and Platinum. She uses a Drifblim, a Gengar, and a Mismagius. In Platinum, Drifblim is swapped for Dusclops, which can be a surprising threat. Furthermore, in Platinum, she switches from being the game's fifth gym leader to its third. Her early placement is crazy, as her team is mostly unchanged and there are fewer options to counter her at this point in the game.

Fantina's Gengar, who is ridiculously fast, will wreak absolute havoc with Confuse Ray, as will Mismagius. Her Mismagius also knows Shadow Ball, which does a ton of damage. She's no joke, and her earlier placement in the game means she's slightly more difficult than Morty.

5 5/10 Elesa (Unova)

Elesa from Pokémon standing against an arena backdrop.

Elesa from Pokémon Black & White makes use of the very solid Electric type. Electric is a great type in Pokémon because it has only one weakness: Ground. With that in mind, two of Elesa's three Pokémon are Emolga, who is an Electric/Flying type. The added Flying type makes Emolga immune to Ground damage.

Elesa also has a tendency to use Volt Switch, which makes hitting her team's weaknesses even harder. Her third Pokémon, a Zebstrika, is a beast in its own right. Plus, since Elesa is only the fourth gym leader in the Unova region, it can be hard to find counters by the time you have to fight her. There simply aren't many Rock, Ice, or Ground type Pokémon available. Most players have to use brute force to get through her, adding to her frustrating difficulty.

4 4/10 Clair (Johto)

Clair from Pokémon standing against an arena backdrop.

Clair is the leader of Blackthorn City Gym and the final gym leader in Pokémon Gold, Silver, and Crystal. She uses three Dragonair and a Kingdra. Each Dragonair has slightly different coverage, with one of them knowing Surf, one knowing Thunderbolt, and one knowing Ice Beam. Her Kingdra is especially strong. Its Water type negates Dragon's weakness to Ice. Kingdra's only Weakness in Generation Two is Dragon, which it also hits super-effectively.

Clair's penchant for inflicting paralysis sets up nicely for her Kingdra's devastating Hyper Beam. Brute force is often the only method for taking Kingdra down. Steel-type Pokémon like Magneton and Scizor work well by resisting many of Clair's damage types, but that's about it in terms of counters.

3 3/10 Norman (Hoenn)

Norman from Pokémon standing against an arena backdrop.

Norman is the player character's father in Ruby, Sapphire, and Emerald and the fifth gym leader of the Hoenn region. He's ranked highly because he's a serious roadblock with little to no reliable counters.

Norman is an infamous gym leader thanks to his two Slakings and their moves Slack Off and Yawn. Slack Off restores half of its user's total HP. Yawn causes the opponent to fall asleep after a turn. Despite the fact that Slaking can only move once every other turn, its titanic attack and HP stats more than make up for this. This gym's Normal-type Pokémon are only weak to the Fighting type, and there are no Fighting Pokémon strong enough to make much of a dent in Slaking's HP at this stage of the game.

2 2/10 Sabrina (Kanto)

Sabrina from Pokémon standing against an arena backdrop.

Sabrina is especially tough in Generation One thanks to the dominance of the Psychic-type. In Generation One, Psychic had only one weakness, that being the Bug-type. What Generation One did not have, however, was a Bug-type move that did any real damage. Therefore, when it came to options for countering the Psychic type, there simply weren't any. This is why Sabrina is so notoriously difficult.

As for Sabrina's team, in Red & Blue, she has a Kadabra, a Mr. Mime, a Venomoth, and an Alakazam. Along with their awesome Psychic moves, Kadabra and Alakazam know Recover, which can restore their HP by half. And because both of them are very fast, they will be able to use them. Plus, her Mr. Mime can defend her team with Reflect and Light Screen, making her even harder to take down.

1 1/10 Blue (Kanto)

Blue from Pokémon standing against an arena backdrop.

Blue takes over the Viridian City gym after Team Rocket is disbanded. In addition to being generally tough, Blue doesn't stick to one type. He uses an Exeggutor, an Alakazam, an Arcanine, a Rhydon, a Gyarados, and a Pidgeot. His team has outstanding coverage. No one weakness can be relied on or exploited, making Blue inherently stronger than any other gym leader.

Blue's high-level Pokémon also have incredible moves, including Solar Beam, Recover, Psychic, Earthquake, Hydro Pump, and Hyper Beam. Blue's sheer strength is exceeded only by that of Red who, if he were a gym leader, would certainly be ranked at #1.