Battling the bosses is a mandatory step in the monthly Team Rocket Special Research, so if you want a Shadow Legendary Pokémon, you’ll have to take them on.
Cliff is one of the Team Rocket gym leaders. He uses a mix of normal- and ground-type Pokémon, with some other types thrown in there.
How do I find Cliff?
Take down Team Rocket grunts at PokéStops to get six Mysterious Components. After obtaining six, they’ll piece together into a tracker to find a Team Rocket leader. You’ll battle one of the three gym leaders at various PokéStops marked by