Starfall Circus is the seventh Challenge Event, introduced June 10, 2021 (see forum) and later included in th Challenge Festival II. It opens Thursday 7:00 UTC and continues to the following Monday.
Most enemies are 
Holy (see graph below) and many have full Elemental Barrier.
There is a unique Event Effect added, Starfall: each 5 turns it deals 100 / 150 / 200 damage (depending on the difficulty) to all Heroes, changes their element to the one they are strong against, and prevents the use of 2 battle items for 3 turns.
Event Heroes[]
| 3* Heroes | 4* Heroes | 5* Heroes |
|---|---|---|
| Candy Holy
|
D'Andre Holy
|
Bobo  Ice
|
Whacker  Nature
|
Eichbelborg  Fire
|
Director Zuri Holy
|
| Marcel Nature
|
Eiora & Fluffy Nature
| |
| Emilio Fire
| ||
| Faline Holy
| ||
| Theobald Ice
|
The special event heroes are all part of the Starfall Family and get a Family bonus when in a player’s team. Bonus for 1/2/3 (different) Heroes: 50%/75%/100% chance to cleanse the Hero's most recent cleansable status ailment at the end of each turn.
Heroes of the Starfall Family also have increased attack, defense, and health (all +20 %) in the Starfall Circus' stages.
Event Stages[]
Cap put together graphiscs of the levels and enemies in Starfall Circus (as it used to be standalone):
