7 tiers. 1-7 stars.
Imperial Chimaera event is updated for 3v3. Link
Imperial Chimaera is going to run 8 days this time so that it overlaps with the Home One event. [via CG]
Imperial Chimaera has been confirmed to return on Jan 18th. It will end before Home One starts.
Rumors of Imperial Chimaera returning on Jan 18th (from datamined info).
Lots of questions around when this event will return. A lot of people think that there won't be another Home One event before it returns (because CG). If it follows the Legendary cycle, it may not return until around Feb 8th. We'll know more at the beginning of January. Since this is a new event type, it's up in the air when it'll return.