Hoopa Quest
The Hoopa Quest was released on 12/01/2018 as a new feature.
In order to trigger the Hoopa Quest, you need to be at Trainerlevel 20 or higher and it can only be activated when you do not have an active Rowan quest at the lab. If you meet those requirements, you can repeat the Quest as often as you like. Hatching a Hoopa egg will not break your Shiny Chain as Hoopa has its own chain.
Every 50th Hoopa egg you obtain will automatically hatch as shiny.
The Quest
To start the Quest you need to free the banned Hoopa from its Treasure Box by playing the Treasure Hunt Game at the Game Center.
After freeing Hoopa, the real Quest begins and Professor Rowan asks you to find five Prison Rings which are spread randomly all over PokéHeroes, excluding the forums and special event pages. Those five golden rings will remain at their locations after the quest has been started and you collect them by clicking on one.
The Quest is mobile and desktop friendly and it doesn't require scrolling, so if you visit a site and don't see a golden ring on the current screen, you can stop your search on this page and move on to the next one.
After finding all five Prison Rings, Professor Rowan will ban Hoopa back into a Treasure Box where you can free it again later and you receive a Hoopa egg if you have a free spot in your party.