As the season of lights continues with the greedy glutton event in Pokemon Go, team rocket decides to create some trouble by converting more Pokemons into shadows. Stop this takeover by participating in the event and battle against Grunts, Leaders, and Giovanni to rescue the shadow Pokemons.
In this event, trainers can also enjoy some amazing bonuses which are listed below.
New Pokemon debuts

Team Rocket is back with a bunch of new shadow Pokemons making their debut . Grunts, leaders and Giovanni have changed their lineups and you can encounter their first Pokemon after defeating them. The new pool of Pokemon includes Shadow Onix, Shadow Natu, Shadow Wailmer, and Shadow Golet , which will be available via grunts. The Go Rocket leaders have a new lineup of shadows, while the boss, Giovanni, is back with shadow Mewtwo.
Note: Shadow Pokemons from Go Rocket leaders can be shiny.
For Trainers that snag a 12 km Egg from Team GO Rocket Leaders, the egg pool has been changed up. This includes the first time of possibly hatching a Shiny Pawniard.
Event Bonuses

Team GO Rocket will be appearing more frequently at PokéStops and in balloons. You can use a Charged TM to help a Shadow Pokémon forget the Charged Attack Frustration. As the Greedy Gluttons event will be active as well , it's bonuses will also be available.
Event Boxes

Three Team GO Rocket-focused boxes will be released during the event.
Training Box (125 PokéCoins, purchase limit 3): 3 Mysterious Components and 1 Egg Incubator.
GO Rocket Box (900 PokéCoins, purchase limit 3): 3 Max Potions, 3 Rocket Radars, 3 Super Incubators, and 3 Max Revives.
Legend Box (3,600 PokéCoins, purchase limit 1): 2 Elite Fast TMs, 2 Elite Charged TMs, 10 Rocket Radars, and 6 Super Incubators.
Shadow Pokemons and Eggs

The following Pokémon will be transformed into Shadow Pokémon which can be caught after successful battles with Team GO Rocket Grunts- Shadow Alolan Diglett, Shadow Onix, Shadow Natu, Shadow Wailmer, Shadow Golett, and more.
Go Rocket Leaders:
Arlo - shadow mawile*
Cliff - shadow machop*
Sierra - shadow sableye*
Egg pool:
Larvitar*, Absol*, Skorupi*, Sandile, Scraggy, Pawniard*, Vullaby*, Deino*, Pancham, Skrelp, and Salandit.
Note:
– * denotes that the Pokemon can be obtained in its shiny form.
– Shiny Pawniard will make its debut, which will be available only through eggs.
Field Research Tasks

Trainers will be able to get Mysterious Rocket Components by completing event-exclusive field research. These components can be combined to form a Rocket Radar, used to find Rocket Leaders. This research can be obtained by spinning pokestops.
Task: Defeat 2 Go Rocket Grunts
Reward: 1 Mysterious Rocket Component
How to maximize this event

Try defeating as many Grunts as possible in order to get some good shadow Pokemons.
Try defeating some Rocket Leaders as they can give you access to some good shadow Pokemons which have a potential of becoming shiny. They also give 12 km eggs .
Hatch the 12 km eggs using Star Piece for additional Stardust gain
Don't forget to complete the special research which will lead to an encounter with Giovanni (On defeating him you can catch Shadow Mewtwo).
Lastly, T.M away frustration from the desired shadow Pokemons as you won't be able to after this Event.