Most Imaginarium Theater pages tell you which characters the season wants. Almost none tell you what actually decides the clear: how many bodies you need on the bench, and what each extra body is worth in stats. This one does both.
Quick answer: The September 2026 season of Imaginarium Theater runs from 1 September 2026 to 1 October 2026 and its three required elements are Hydro, Electro and Dendro. The Opening Characters are Columbina, Xingqiu, Cyno, Kuki Shinobu, Lauma and Kaveh, and the Special Guest Stars are Odette, Sandrone, Sucrose and Nicole. The roster wall is the real gate: 8 characters for Easy, 12 for Normal, 16 for Hard, 22 for Visionary and 28 for Lunar Mode, all at Lv. 60 for the two easiest tiers and Lv. 70 from Hard upward. Talent levels and artifacts do not count toward that requirement at all. Every character you add above the minimum is worth 2 Blessing Levels, and each Blessing Level grants +800 Max HP, +50 ATK, +50 DEF and +20 Elemental Mastery for the whole run.
Article status: verified on 10 September 2026 against the official in-game Version 7.0 Update Details announcement for Genshin Impact (hk4e_global announcement 21857, full text read), plus the community wiki's mechanics and Season 27 stage data for the parts HoYoverse does not publish in the announcement. Version 7.0 "Everwinter Without Mercy" is the live version at the time of writing.
What are the Imaginarium Theater required elements in September 2026?
Hydro, Electro and Dendro.
That comes from the official Version 7.0 Update Details notice, the only first-party source for the season. HoYoverse publishes no standalone Imaginarium Theater announcement — of the 29 notices live in the in-game feed on 10 September 2026, exactly one carries the season data:
"Update Scheduled for September 1 — After the Version 7.0 update, a new season of Imaginarium Theater will be available on September 1, 2026. Required Elemental Types: Hydro, Electro, and Dendro"
That element trio matters more than it looks. Hydro plus Electro is Electro-Charged, Hydro plus Dendro is Bloom, and Electro plus Dendro is Quicken and Aggravate — every pairing this season produces a real reaction, which is not always true, since some seasons deliberately pick elements with no reaction between them. The Brilliant Blessing events offered mid-run are built around those reactions, so a roster that can trigger them beats a roster of individually stronger characters who never interact.
Who are the Opening Characters and Special Guest Stars?
The same announcement lists both groups.
Opening Characters: Columbina, Xingqiu, Cyno, Kuki Shinobu, Lauma and Kaveh.
Special Guest Stars: Odette, Sandrone, Sucrose and Nicole.
The difference between the two lists is the most misread rule in the mode.
Opening Characters form your starting Principal Cast, and you do not need to own them — if you lack Columbina or Lauma, the game hands you a trial version. But if you do own one, you get a season-long buff: HP, ATK and DEF increased by 20% for the duration of the season, applying both inside and outside the theater. That is a free overworld and Abyss buff for a character you were probably already using.
Special Guest Stars work the opposite way. They ignore the Hydro, Electro and Dendro restriction — that is the point of them — but you must own them or borrow them through a friend's Supporting Cast, because there is no trial version. The part worth knowing before you build around them: the buff effects received by Special Guest Stars are increased by 100%. A Guest Star in your lineup receives double the Blessing Level stats everyone else gets. If you own Sandrone or Odette and treat them as off-element filler, you are leaving the largest stat multiplier in the mode on the table.
One more line from the announcement, purely cosmetic but frequently searched:
"After the new season of Imaginarium Theater begins, the characters Flins, Columbina, Kirara, and Illuga will each gain a new 'Thespian Trick' that can be exchanged from the NPC Wolfy."
Thespian Tricks are Photo Mode poses, bought from Wolfy with Toy Medals earned in Acts 3, 6 and 8.
How many characters do you need for each difficulty?
This is the wall almost everyone hits, and it has nothing to do with power level.
| Difficulty | Acts | Minimum roster | Maximum roster | Minimum character level |
|---|---|---|---|---|
| Easy Mode | 3 | 8 | 10 | Lv. 60 |
| Normal Mode | 6 | 12 | 14 | Lv. 60 |
| Hard Mode | 8 | 16 | 20 | Lv. 70 |
| Visionary Mode | 10 | 22 | 26 | Lv. 70 |
| Lunar Mode | 12 | 28 | 32 | Lv. 70 |
Visionary Mode only unlocks after you clear Hard, and Lunar Mode only unlocks after you clear Visionary, so you cannot skip straight to the top tier in a fresh season.
Two things make that table less painful than it reads.
First, the requirement is a level requirement, not a build requirement. A Lv. 70 character with no talent levels and four random four-star artifacts satisfies the roster count as well as a fully built one. The Alternate Cast exists to be spent — every stage consumes Vigor, each character has two, and once both are gone that character is out for the run. Bodies are a consumable here.
Second, every stage takes four characters, but you can finish a stage with fewer than four on the field. Benching a weak Lv. 70 filler is legal, and preserves their Vigor.
The one place people over-invest is talents, which cost Resin every level. If you are short of bodies with the season half gone, ascend wide and shallow rather than deep.
Why should you add more characters than the minimum?
Because the extra slots are the cheapest stats in the game — and this is the number competing guides do not print.
Every character added to the Alternate Cast above the required number increases Blessing Level by 2. Obtaining or upgrading any Brilliant Blessing during a run adds 1 more. Each Blessing Level then grants, for every character in the performance:
- Max HP +800
- ATK +50
- DEF +50
- Elemental Mastery +20
Run the arithmetic on Hard Mode. The minimum is 16 and the cap is 20, so four spare bodies is 8 Blessing Levels, which is +6,400 Max HP, +400 ATK, +400 DEF and +160 Elemental Mastery on everyone you field, before a single Brilliant Blessing is picked up. On Lunar Mode the gap between 28 and 32 gives the same 8 levels. On a Dendro or Electro-Charged team, 160 Elemental Mastery on every unit is not a rounding error — it is roughly the value of a full artifact main stat, applied party-wide, for free.
So if the choice is between a fifth artifact reroll and ascending one more Hydro unit to Lv. 70, ascend — and if that character is a Special Guest Star, the 100% buff multiplier stacks on top.
What is the cheapest way to fill a Hydro, Electro and Dendro roster?
Three levers, in order of how much Resin they cost you.
Four-stars first. Hydro, Electro and Dendro is one of the most four-star-dense element trios in the game. Barbara, Xingqiu and Candace cover Hydro; Lisa, Fischl, Razor, Beidou, Dori, Kujou Sara and Kuki Shinobu cover Electro; Collei, Yaoyao, Kirara and Kaveh cover Dendro. Lisa is free on every account from the quest "Sparks Amongst the Pages." Most accounts past Adventure Rank 35 own more of these than they think — sitting at Lv. 20 in the roster screen, not missing.
The Traveler. The Traveler's element is set at a Statue of the Seven, so one character can be pointed at whichever required element you are shortest on. One hard restriction: the Traveler cannot be assigned as a Supporting Cast member for friends. Players this season report using the Traveler to cover a required element slot in their own Alternate Cast and level one fewer character — worth confirming on your own roster screen, since HoYoverse does not spell this out.
Friends' Supporting Cast. You can set up to 7 characters as Supporting Cast and each can be borrowed up to 15 times per season, but a Supporting Cast character cannot simultaneously sit in your own Alternate Cast — it covers a gap, it does not double-dip.
Which bosses are in the September 2026 season, and what beats them?
Season 27 uses a four-boss ladder across Acts 3, 6, 8 and 10, each with a published element advantage. Enemy levels below are the Hard and Visionary tiers.
| Act | Boss | Enemy level | Time limit | Star Challenge | Advantage |
|---|---|---|---|---|---|
| 3 | Jadeplume Terrorshroom | 90 | 105s | 70s | Electro characters |
| 6 | Emperor of Fire and Iron | 92 | 95s | 65s | Hydro characters, elemental effects |
| 8 | Battle-Hardened Pipilpan Idol | 95 | 110s | 75s | Electro-Charged reactions |
| 10 | Radiant Moonfly | 100 | 105s | 70s | Characters who heal |
Read that column downward and the season's shape is obvious. Electro carries Act 3, Hydro carries Act 6, and Act 8 explicitly rewards the Hydro-plus-Electro reaction — an Electro-Charged core is the strongest single investment this month. Act 10 is the outlier: the Radiant Moonfly's Radiant Cocoon is escaped by healing back to full HP quickly, so a roster with zero healers walls there regardless of damage. If you are planning 28 bodies for Lunar Mode, put at least two healers among them.
Lunar Mode adds two optional Arcana Challenges on top of the ten Acts — listed as Arcanum 1 and Arcanum 2 in the reward table — unlocked after Acts 3 and 6, attemptable any time before Act 10, and roughly as hard as the final Act.
What rewards does a full clear give?
Per season, a complete Lunar Mode run pays 1,000 Primogems and 600,000 Mora, plus 3 Toy Medals, 26 Sanctifying Essence, 28 Sanctifying Unction, 1 Transient Resin, 2 Sanctifying Elixir and a stack of talent books. Acts 1 through 10 account for 800 of those Primogems; the two Arcana Challenges add 100 each.
The first time you clear each Act you also collect a one-off Debut set worth 1,800 Primogems, 960,000 Mora, 6 Fragile Resin, 60 Hero's Wit, one Crown of Insight, one Midlander Billet Trove and one Borderland Billet Trove. The Crown of Insight is the headline — it drops from the first clear of Act 10.
Star Challenges are the optional timers above and pay separately: three Stella in a run gives 8 Sanctifying Unction, six gives a Transient Resin, and nine and twelve each give a Sanctifying Elixir.
How do you unlock Imaginarium Theater?
Reach Adventure Rank 35 and complete the quest "Unbegun, Unending Story." The mode itself lives in the Theater Lobby of the Mondstadt Library, previously known as the Mysterious Room, and Wolfy is the concierge you talk to.
Once unlocked it is permanent, and it resets on the first day of every month with a new element trio, Opening Characters and Guest Stars — which is why the September answer will not be the October answer.
When does the September 2026 season end?
The current season began 1 September 2026 and runs to 1 October 2026, when the automatic monthly reset swaps the required elements and the cast.
The useful cross-reference is the patch calendar: the Version 7.1 Special Program is scheduled for 12 September 2026 and the update lands later in the month, so a new banner and new ascension priorities will compete for your Resin before the season closes. Our Version 7.1 release date breakdown has the evidence for the maintenance window, and the September 2026 banner schedule covers what is running until then.
More Genshin Impact guides
- Genshin Impact codes for September 2026 — active and expired, with drop times
- Genshin 7.1 livestream codes — the 24-hour redemption window explained
- Genshin anniversary 2026 rewards — what is confirmed and what is not
- Genshin banner schedule for September 2026 — current phase timings
Frequently Asked Questions
What are the Imaginarium Theater required elements in September 2026? Hydro, Electro and Dendro, confirmed by the official Version 7.0 Update Details announcement. The season began on 1 September 2026 and resets on 1 October 2026.
How many characters do I need for Imaginarium Theater? Eight for Easy Mode, 12 for Normal, 16 for Hard, 22 for Visionary and 28 for Lunar Mode. The maximums are 10, 14, 20, 26 and 32 respectively, and every character above the minimum adds 2 Blessing Levels.
What level do my characters need to be? Lv. 60 for Easy and Normal Mode, Lv. 70 for Hard, Visionary and Lunar Mode. Talent levels and artifacts are not checked at all — only character level and element.
Do I need to own the Opening Characters? No. Columbina, Xingqiu, Cyno, Kuki Shinobu, Lauma and Kaveh are all available as trial versions. Owning one grants a 20% HP, ATK and DEF buff for the whole season, which applies outside the theater as well.
Do I need to own the Special Guest Stars? Yes. Odette, Sandrone, Sucrose and Nicole have no trial versions, so you must own them or borrow them through a friend's Supporting Cast. In exchange, buff effects they receive are increased by 100%.
Can I use the Traveler in Imaginarium Theater? The Traveler is the one character that cannot be set as a Supporting Cast member for friends. Because the Traveler's element is chosen at a Statue of the Seven, players commonly point it at whichever required element they are short on for their own roster.
How many Primogems does a full Imaginarium Theater clear give? 1,000 Primogems per season from a complete Lunar Mode run, plus a one-time first-clear total of 1,800 Primogems and a Crown of Insight from Act 10.
Does Imaginarium Theater reset every month? Yes. It resets on the first day of every month, and the required elements, Opening Characters and Special Guest Stars all change with it.
Which team should I build for Act 8? Act 8 gives Electro-Charged reactions an advantage against the Battle-Hardened Pipilpan Idol, so a Hydro applier paired with an Electro applier is the intended answer — and that core also covers Act 3's Electro advantage and Act 6's Hydro advantage.
