Arknights: Endfield Si: Lore, Banner Speculation and Everything We Know So Far

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Few characters in Arknights: Endfield have generated as much early hype as Si. She was teased as a playable Operator as far back as the Version 1.2 livestream, quietly helped the player characters behind the scenes for most of the main story, and finally stepped into the spotlight in Version 1.4's Yinglung Pass storyline — all without a single skill being shown. Her name alone, the Feranmut Proxy, is enough to set the lore community buzzing, because it ties her to the ancient beings at the core of the Arknights universe. This guide collects everything we know so far: her confirmed lore, her story role, the identity theories, the expected banner window, and how many pulls you should be saving.

Si Quick Overview

Who Is Si? Lore and Identity

The Feranmut Proxy Explained

The key to Si's identity is her title. According to the character database at EndfieldTools.DEV, a Feranmut Proxy is a humanoid avatar of a Feranmut — a race whose powers are unrelated to Originium Arts and who possess full immunity to Oripathy. In the Arknights universe, Feranmuts are ancient, god-like beings that predate most recorded civilization, and a "proxy" is essentially their chosen vessel or representative walking among mortals. That single sentence does a lot of work: it places Si outside the normal Arts-based power system, explains why she behaves differently from every other Operator, and sets up a major narrative question — which Feranmut does she represent?

Her Role in the Story So Far

Si has been in the story much longer than most players realize. EndfieldTools confirms that she has been quietly assisting Arcane and the Endfield Crisis Team since the Tales of Old questline, appearing at Marker Stone in the form of a Butterfly Ink Spirit. That framing — a subtle guide who nudges the party without revealing herself — matches her 1.4 appearance perfectly. She is not a random new character; she is a long-standing background presence who finally chose to show herself.

The Butterfly Ink Spirit form is worth dwelling on. In Endfield's story presentation, spirits and anomalies are common, but a Feranmut-linked spirit that consistently appears at Marker Stone — a location tied to the story's early guidance — implies Si has been watching the Endministrator's journey from the very beginning. Combined with her eventual reveal as the Feranmut Proxy, the implication is that the game's opening guidance, not just the Wuling arc, may have been part of her design all along. Players who revisit the Tales of Old questline after the Version 1.4 reveal report noticing her presence retroactively, which is exactly the kind of quiet foreshadowing Hypergryph is known for.

Appearance in Version 1.4

During the Yinglung Pass questline in Version 1.4, Si finally appears in her true form: a green-haired female figure with dragon-like horns, first seen alongside the story's exploration of the Wuling region's dangers. The 1.4 livestream confirmed her as a playable Operator in a future version — the same "preview slot" treatment that Liino received before her August 9 banner. For the lore, this debut also plants her firmly in the middle of the Wuling narrative, which is expected to expand beyond Yinglung Pass into a new region in Version 1.5.

The Feranmut Connection in the Arknights Universe

What Feranmuts Mean in Arknights Lore

Feranmuts are the closest thing the Arknights world has to deities. In the original Arknights, their territory and influence shape entire nations: a significant portion of Sami is said to sit upon the body of a slumbering Feranmut, and Kazdel once housed a Feranmut whose consciousness was fragmented across artifacts. They are beings whose power operates outside the Originium Arts system, which is exactly why the definition used for Si — "powers unrelated to Originium Arts and full immunity to Oripathy" — matters. A playable Feranmut-adjacent Operator would be a first for the franchise, and it explains the enormous community interest.

The Sui Theory

The most popular community theory ties Si to the Sui, the seasonal Feranmut from the original Arknights whose fragments manifest as the twelve (some reports suggest thirteen) siblings associated with the Chinese zodiac. Si's dragon horns, her mysterious identity, and her proxy status all fit the Sui's pattern of manifesting through avatars and fragments. Early unconfirmed reports even describe her as a "13th agent of the Sui beasts." None of this is officially confirmed — Hypergryph has not stated which Feranmut Si serves — but it is the leading theory among lore enthusiasts on Reddit and community wikis, and it colors how players expect her kit and personality to be designed.

What Her Proxy Status Could Mean for Gameplay

A Kit Outside the Arts System

Feranmut powers operate outside the Originium Arts system, and Feranmuts are immune to Oripathy — the disease that defines most of the Arknights setting. Community theory-building assumes Si's kit will reflect that: expect mechanics that play differently from standard Arts-based units, possibly ignoring resistance rules, bypassing normal anomaly constraints, or introducing a unique resource system the way Arcane's dual-form stat ratio does. Until Hypergryph shows her skill list, this is speculation — but it is speculation grounded in how the lore defines her species, and it is why so many players assume she will not be a "generic" DPS or support.

Element and Class Speculation in Context

Two candidate builds dominate the discussion. The most common claim from early reports is a Heat-element main DPS — a slot the roster genuinely lacks, which would explain why the game is holding such a prominent banner position for her. The other suggestion is a Nature Vanguard, filling the roster's biggest open role while keeping her off-field utility flavor. Either way, her expected Version 1.5 timing and preview-slot treatment suggest she will arrive as a marquee unit with a signature weapon banner of her own, so plan for the usual 80-pull Arsenal guarantee if you want her best-in-slot weapon. A quick summary of where each theory stands:

Si Banner Speculation

Expected Release Version

Si's banner timing is the subject of intense speculation, and the evidence points one direction. She was teased as playable in the Version 1.2 livestream, confirmed again in the Version 1.4 preview, and appears in the 1.4 story. Historically, that combination of story appearance plus playable preview slot has meant a one-version wait before release — it is exactly the pattern Liino followed. The Game8 Arknights: Endfield wiki currently estimates Si's banner at August 30, 2026, making Version 1.5 (late August – early September) the consensus expectation. Nothing is officially dated yet.

Possible Element, Class and Role

Si's kit is completely unconfirmed — no skills, no numbers, no weapon type have been shown. What exists is community speculation layered on top of the roadmap:

• Heat DPS (most common claim): early unverified reports describe Si as a benchmark Heat-element main DPS, which would give the Heat element its first real carry and explain why the game is saving a major slot for her.

• Nature Vanguard (community question): other players note the roster still lacks a strong Nature Vanguard and wonder whether she fills that niche instead.

• Story-significant role: her Feranmut connection suggests she may also bring a unique mechanic tied to her non-Originium power set, the way Feranmut lore works in the original Arknights.

Treat all of the above as speculation. The only guarantee is that she will follow the standard Chartered banner rules.

How Her Banner Will Likely Work

When Si's banner arrives, it will use the standard Chartered Headhunting rules: a single pull costs 500 Oroberyl (10-pull: 5,000), soft pity guarantees a 6-star at 80 pulls (50/50 on the rate-up, counter carries over between banners), and hard pity guarantees Si at 120 pulls (60,000 Oroberyl) — a guarantee that resets when the banner ends. Expect the usual milestones: a free 10-pull at 30 pulls, a Headhunting Dossier (free 10-pull for the next banner) at 60, and a bonus Potential token at 240 pulls. If you plan to commit to her, buying Origeometry at discounted rates from Topuplist's Arknights: Endfield top-up page before the banner drops is the cheapest way to fund the guarantee.

Should You Save for Si?

Arguments For Saving

• Lore value: as the first confirmed Feranmut-Proxy playable unit, she is a historically significant account piece for collectors and lore fans.

• Expected power: if the Heat DPS reports are accurate, she would be the element's first top-tier carry — high pull priority for anyone building a Heat team.

• The opportunity cost window: skipping 1.4's Phase 2 (Liino) leaves your soft-pity counter ready to carry into her banner.

• Roadmap momentum: her preview-slot treatment plus a likely signature weapon mean she is being positioned as a major release, not a filler banner.

Arguments Against

• Zero kit information: as of this writing, her kit, element and class are unknown. Pulling targets with no information is how regret happens.

• Liino is excellent right now: Liino's universal support kit is a proven T0 upgrade for Electric teams, and she is available for a full month (August 9–30) while Si remains hypothetical.

• Later targets are coming: the Sarkaz Archer, Hongshan Imperial Guard, M3 and Manor Mistress are all on the roadmap; if Si does not fit your roster, one of them probably will.

Who Si Might Be For

If you are a lore-driven player, a Heat team owner, or simply want to enter Version 1.5 with a full 120-pull guarantee, Si is the obvious savings target. If your account is missing a support like Liino, or you are undecided about the entire 1.5 lineup, hold your Oroberyl and wait for the official livestream — the kit reveal will make the decision much easier.

The bottom line: Si is a lore-significant, likely high-power Operator, but she is also the least-known major unit on the roadmap. If the idea of a Feranmut Proxy carry excites you, start banking your 60,000 Oroberyl now and let your soft pity carry into her banner. If you need an immediate team upgrade, Liino is on the field for the entire month of August. Either way, do not start a 120-pull commitment on a banner whose kit you have never seen — and if you decide to go all-in, funding the guarantee with discounted Origeometry from Topuplist's Arknights: Endfield top-up page makes each pull cheaper than buying in-game.

What Could Still Change

Everything above is a snapshot, not a promise. Si's element and class could shift, the August 30 estimate could move a week either way, and Hypergryph could surprise us with a different headliner entirely — the Sarkaz Archer's teaser was strong enough that some players expect her to carry 1.5's regional story instead. The official livestream before Version 1.5 is where the speculation ends: expect kit details, skill animations, banner dates and possibly a redeem code in one broadcast. Until then, the safest play is simple — keep your pity counter clean and your Oroberyl banked.

FAQ

Who is Si in Arknights: Endfield?

Si is the Feranmut Proxy — a humanoid avatar of a Feranmut, a race with powers unrelated to Originium Arts and full immunity to Oripathy. She has been quietly assisting Arcane and the Endfield Crisis Team since the Tales of Old questline, appearing at Marker Stone as a Butterfly Ink Spirit, and debuts in person during the Version 1.4 Yinglung Pass story.

When will Si be released?

No official date has been announced. She is expected in Version 1.5 (late August – early September 2026), with Game8 estimating her banner at August 30, 2026.

What is Si's element and class?

Unconfirmed. Community speculation ranges from a Heat-element main DPS to a Nature Vanguard; no official kit information has been released.

Is Si connected to the Sui Feranmut?

The leading community theory connects her to the Sui, the seasonal Feranmut from the original Arknights, with early reports describing her as a "13th agent of the Sui beasts." Hypergryph has not confirmed this.

How many pulls should I save for Si?

120 pulls (60,000 Oroberyl) to guarantee her. Soft pity guarantees a 6-star at 80 pulls and carries over between banners, but the 120-pull hard guarantee resets when her banner ends.

Should I pull Liino now or save for Si?

If you run Electric or anomaly teams, Liino (August 9–30) is a proven T0 upgrade and a strong use of pulls. If you do not need her and want Si, skipping 1.4 Phase 2 and saving is a completely valid plan.

What did the Version 1.4 livestream actually show about Si?

The livestream revealed her name (Si), confirmed her as a playable Operator in a future version, and showed her in the playable-preview slot alongside the new-region teasers. No kit details — skills, element or class — were shown.

Does Si appear in Version 1.4 right now?

Yes. She appears in her true form during the Yinglung Pass questline in Version 1.4, and players who have not caught up can meet her there today.

Where can I stock up on Origeometry while saving?

Top up through Topuplist — the Arknights: Endfield top-up page offers discounted Origeometry packs, the Monthly Pass and bundles so your Si savings go further.