These past Legendary Pokemon return to Tier 5 Raid Battles and they bring their shiny variants!

Cresselia 

Cresselia will be available in Raid Battles from May 27, 2019 at 1:00 pm PDT until June 18, 2019 at 1:00 pm PDT.

For the first time, you may encounter a shiny Cresselia!

Kyogre

Kyogre will be available in Raid Battles from June 18, 2019 at 1:00 pm PDT until June 27, 2019 at 1:00 pm PDT.

You may encounter a shiny Kyogre!

Groudon 

Groudon will be available in Raid Battles from June 27, 2019 at 1:00 pm PDT until July 10, 2019 at 1:00 pm PDT.

You may encounter a shiny Groudon!

My thoughts

Kyogre and Groudon are among the best Legendary Pokemon around, here we have another shot at capturing some good IV Pokemon, collecting candy for powering up and hunt for that shiny. Cresselia is not that useful but its new shiny form is a nice incentive.