Arknights Endfield 1.6 Sanctuary of Ink: Si, Argent Flow & Steam Date

The Arknights: Endfield Version 1.6 Sanctuary of Ink update arrives on October 15, 2026, and it lands on the same day the game launches on Steam. At gamemarket.gg, we went through everything revealed in the Version 1.6 Special Program on October 6: a new region set inside an ink painting, two new operators in Si and Argent Flow, an inn management event, a new season of Contingency Contract and a long list of quality-of-life changes. The broadcast also ended with a tease that long-time Arknights fans will not want to miss. Here is what Sanctuary of Ink adds, how its new operators work and what to prepare before October 15.

Steam Launch and Cross-Progression

The first headline is not about content at all. Arknights: Endfield arrives on Steam on October 15, the same day Version 1.6 goes live.

For existing players, the key detail is that progress carries over across platforms. You do not need to start a new account to play on Steam, so anyone moving to PC can pick up their current save on Talos-II. For newcomers, it means the Steam launch lines up with a fresh version, a new region and two new banners, which makes it a convenient starting point.

A New Region Inside Si's Painting

Sanctuary of Ink takes the story somewhere Endfield has not been before: the Painting of Si, a hidden realm drawn in an Eastern ink-painting style. Its landscape includes mountains, painted creatures and a countryside inn called Yuanyuan Manor Inn, run by Si herself.

The story picks up with the Endministrator injured and recovering at the inn under Si's care. Strange phenomena start appearing in the surrounding mountains, and looking into them leads back to events from ten years ago, tied to the Endministrator's past with Argent Flow. The search for a way to cure the Endministrator runs through the whole chapter.

Exploration has its own twist. Instead of only walking and climbing, you use Si's brush to restore broken paths by drawing them back into the painting. The region also includes Chinese chess puzzles, which fits its art direction and gives the area a different rhythm from earlier zones.

Si: The Innkeeper Who Paints

Si is a 6-star Cryo Supporter and the owner of Yuanyuan Manor Inn. She is also the artist behind the painting itself, which makes her central to both the story and the new region.

Her kit revolves around a mechanic called Inksoul. Si draws an Inksoul out of an enemy, and the damage and effects dealt to that Inksoul are transferred back to the original target. In practice, that gives your team a second way to hit an enemy, and it is likely to matter most against targets that are hard to reach or protected in some way.

Her support role is clear from the reveal. Si strengthens Cryo and Heat teammates, so her value depends on how many operators of those two elements you already use. One of her skills, Landscape in a Single Brushstroke, also lets her summon Ink Dragons, which adds pressure on top of the Inksoul effect.

Because she is a Supporter, Si is a team-building pick rather than a standalone carry. If your main damage comes from Cryo or Heat operators, she has an obvious slot. If your roster leans on other elements, her buff loses much of its value, and that should shape how much you set aside for her banner.

Argent Flow: The Cavalry Fighter From the Past

Argent Flow is an old acquaintance of the Endministrator, and the second new operator in this version. Where Si works from the back line, he fights up close with sword and spear techniques, charging into battle on his warhorse Nuli.

His ultimate shows off that style best. Argent Flow charges forward on Nuli, then leaps for a powerful finishing strike, combining mounted movement with a single burst of damage at the end.

He also gets his own narrative event that reveals his past. Since the main Sanctuary of Ink story already reaches back ten years into his history with the Endministrator, his event fills in the rest of that relationship.

Full skill descriptions, his element and his exact banner dates have not been listed in English yet. Expect those details closer to his banner, and check his kit in-game before deciding between him and Si.

Banners and Free Headhunting Permits

Si and Argent Flow arrive through successive recruitment events, meaning their banners run one after another rather than at the same time. The exact start dates for each banner have not been confirmed yet.

The good news is that every banner comes with free pulls. Version 1.6 includes login events that give 5 limited Headhunting Permits for each banner period. Those permits only work on the limited banner they belong to, so they are a bonus for the operator you want rather than a reason to pull for one you do not.

The practical plan is simple. Decide early whether Si, Argent Flow or both fit your teams, then save your other currency accordingly. Because the banners are sequential, pulling heavily on the first one can leave you short when the second arrives.

Yuanyuan's Blazing Stoves

The biggest new event is Yuanyuan's Blazing Stoves, an inn management event built around Si's manor. It is a change of pace from combat: you grow crops, raise animals and cook dishes for the inn's guests.

The cultivation side also gets a helping hand. A new Auto-Farmer function assists with farming work, which should cut down on the repetitive tending that farming systems usually involve.

Alongside the inn event, the Special Program also showed a martial arts tournament event and a photography event, so Sanctuary of Ink has more side content than the main story alone.

Contingency Contract: Indigo Experimental Operation

For combat-focused players, the main draw is the return of Contingency Contract. Its new season, Indigo Experimental Operation, keeps the core idea of selectable modifiers but changes how they work.

Each modifier now pairs an advantage with a tactical restriction, so you choose trade-offs rather than simply stacking difficulty. Modifiers can also change enemy attack patterns, which means the same stage can play out differently depending on what you select.

If you played the first season, the structure will feel familiar, and our look at how Contingency Contract debuted as Endfield's endgame mode shows how much the new modifier system builds on it. The main takeaway is that team flexibility matters more this time, since a modifier that restricts one approach may reward another.

Quality-of-Life Changes

Version 1.6 also brings several improvements to everyday play:

• Saved equipment loadouts: store and swap gear sets without re-equipping each piece manually.
• Precise mouse targeting: better target selection on PC, which arrives at a good time with the Steam launch.
• Adjustable combo skill priority: control which combo skills fire first.
• Field equipment from the depot: place field equipment directly from your depot.

Saved loadouts are likely to be the most useful of the four, especially for players who switch between Contingency Contract teams and regular content.

Rhodes Island Is Coming

The Special Program ended with the reveal many players were waiting for. A PV showed that Rhodes Island will travel to Talos-II to help Endfield Industries in a future version, and Warfarin made an appearance in it.

No version number or date was given, so this is a look further ahead rather than part of Sanctuary of Ink. For anyone who played the original Arknights, it is still the most exciting announcement of the broadcast.

Before October 15: Your Checklist

With about a week to go, here is how to prepare:

1. Finish current content: clear what is left of the Umbral Monument stages from October 5 and the rest of the current version before 1.6 replaces it.
2. Count your Cryo and Heat operators: this decides how much Si will add to your teams.
3. Save for the right banner: since Si and Argent Flow arrive one after another, decide your priority before the first banner opens.
4. Log in every banner period: claim the 5 limited Headhunting Permits each time.
5. Set up Steam if you are moving to PC: your progress carries over, so you can switch platforms on launch day.

Sanctuary of Ink is a story-heavy update with a clear standout in Si, a new endgame season and a Steam launch that brings in a wave of new players. Plan your pulls around the elements you already use, and the rest of Version 1.6 will be easy to enjoy at your own pace.

If you want a stronger roster for Version 1.6, you can explore trusted Arknights: Endfield Accounts, keep your events, farming and daily progress on track with reliable Arknights: Endfield Hourly Services, or clear Contingency Contract faster through dependable Arknights: Endfield Boosting.

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