Pokemon GO Leader Cliff counters are your key to taking down this Team Rocket Executive.
Cliff, along with Sierra, Arlo, and infamous Team Rocket boss Giovanni, are the higher tier "executive" class of antagonists trainers can encounter when visiting affected PokeStops. Each one has a specific pool of Pokemon from which they draw their team. Unfortunately, this makes battle difficult, as the type each leader uses per round can change with every unique challenge.
Below you'll find a list of Pokemon Cliff uses, who to bring to beat them, and the safest bet to go with for that round overall.
Pokemon GO Leader Cliff Counters
Cliff's first Pokemon will always be his Pinsir. Fortunately, Pinsir is a simple bug-type, so fire, rock, and flying moves will do the trick. Be aware, however, that Pinsir has fighting moves in its repertoire. This could pose a danger to any rock-types or other fighting-types. The best choices against Pinsir would be Moltres, Chandelure, or even Charizard.
Ultimately, you'll want to bring a fire-type for this first round. Any fire-type will do—and, if kept alive, they could come in handy again in round three.
Round two's pool includes Marowak, Electivire, and Omastar. Clearly, there's a bit of diversity here. Marowak is a ground-type, Electivire is an electric-type, and Omastar is a rock and water-type.
Counters for Marowak include water and grass types such as Blastoise, Tropius, Gyrados and Lugia.
Counters for Electivire are Altered Form Giratina with Ancient Power, Rhyperior, and Flygon. Typically, any ground-type will do fine. Trainers should be advised that this Pokemon tends to have non-electric moves in favor of ice or even fighting.
Counters for Omastar can be tricky as electric-types may find some difficulty with its half-rock typing. Your safest bet is going to be a grass-type like Leafon, Vensaur, Torterra, and the like.
The best type of Pokemon to bring for this round would have to be in the grass-type category. Two of the Pokemon in the round two pool have grass weakness and Electivire, while not weak to grass-types, won't always knock them down outright. You may have that ice-type damage to worry about, however. Make sure the grass-type you choose is hardy.
Taking a grass-type will also help out in round three, as well.
Round three's Pokemon include Tyranitar, Swampert, and Torterra. Again, we see some diversity here. Fortunately, if you heeded the advice in rounds one and two, you may have made this much easier for yourself in round three.
Tyranitar, a dark and rock-type, is especially weak to fighting types. You'll want to bring a Pokemon like Lucario, Machamp, or even another Swampert.
Swampert is a water and ground-type, which means the grass-type you brought along in round two will have its chance to shine again. Other counters include Meganium and Roserade. Just be aware of its charge move which is typically poison.
Torterra is a grass and ground-type, so you may find footing with the fire-type from round one. Moltres does well here, as does Entei and Heatran. Additionally, you may find success with ice-types such as Articuno or Regice.
Since you basically already have Swampert and Torterra covered if you brought along the recommended types, you'll really just need to worry about Tyranitar. Therefore, your third Pokemon should be a fighting-type like those listed above.