Pokemon GO Rolls Out New Shadow Bonus

Pokemon GO rolls out a new Shadow Bonus that makes Shadow Pokemon much more powerful in battle, but there's a catch...

Recent Pokemon GO datamines hinted that another big Team GO Rocket event was on the way and the latest official update from Niantic seems to point in the same direction. Before the rest of the exciting March events kick off, the mobile AR game is rolling out a new change that gives Shadow Pokemon a major damage buff... But there is a catch.
An official announcement from Niantic confirmed that the game is rolling out a new feature called the Shadow Bonus. This will make Shadow Pokemon significantly more powerful in battles, but it will also cause them to take more damage when attacked. This should create a very interesting balance for players to strike as they decide how to use or Purify their Shadow Pokemon.

It the past, it pretty much always made sense to purify a Shadow Pokemon if it was one that you planned to use in battles and make a primary member of your roster. With the new Shadow Bonus, that may not always be the case going forward...

"We’ve received reports of developments regarding Shadow Pokemon. Whatever Team GO Rocket is doing seems to be making these poor Pokemon stronger as long as they remain Shadow Pokemon. Details are as follows.
Shadow Pokemon now deal more damage with their Fast and Charged Attacks, but they also take more damage when attacked.
Powering up a Shadow Pokemon and teaching a Shadow Pokemon an additional Charged Attack now cost less Stardust and Candy.
Legendary Shadow Pokemon that you save from Giovanni are now more powerful.
During certain time periods, Shadow Pokemon might be able to forget the Charged Attack Frustration by learning a different Charged Attack with a Charged TM, though we haven’t figured out when that’ll be possible. Please stay tuned for more details.
Despite our efforts, Team GO Rocket is growing stronger and acquiring even more resources. We’re not sure how they’re doing this, but please know that we’re investigating how to fight back against these ruffians. Let’s stay strong, Trainers!"

It's very interesting that the buff also means the Shadow Legendary creatures captured from Giovanni are now more powerful than ever. This definitely offers some extra motivation to work through the month requirements for that encounter, especially with a powerful Pokemon like Entei up for grabs.
For now, players may want to keep hunting down the best Unova Pokemon in the game if improving their Battle Raid rosters is their primary goal. Be sure to check back in the near future for more Pokemon GO strategy guides, news, and updates. Until then, good luck out there, trainers!