Do limited banners come back Arknights?

W wasn't available in the rerun because W banner was never ran during Darknights Memoir, it was ran during the first Anniversary and the release of chapter 7. That is to say, directly after Darknights Memoir. The banner that ran during Darknights Memoir was always Illusions of the Past.

As for Nian, she only got a banner rerun because players complained that they couldn't easily get her the first time around, which led to the introduction of the spark system and her banner exceptionally getting a rerun. Limited operators will otherwise never get a rerun, only appearing with higher weight proportion in non-rateup of limited banners of the same pool. For example, during the Skadi the Corrupting Heart banner, 70% of the 6-star rolls will be either Skadi or Kal'tsit, and the remaining 30%, also called spooks, will be any other operator in the pool. In those remaining 30%, W will appear only during other banners of the "Anniversary" pool, which Supporter Skadi is, and her name will be weighted five times. That is to say, while everyone only has their name "once" in the ballot, W has her name 5 times. By now, you've probably realized that even so, she's extremely unlikely to appear (5 chances out of however many 6* are in the game at the time including herself + 4) and it's not a very good deal. In other words, you either need to luck out, or save up 300 rolls to buy her in the spark shop. The same will apply to Nian (who will likely share the fivefold name weight with Dusk in a future Chinese New Year pool banner).

Limited Banners function a bit differently than Standard Pool Banners or Normal Event/Feature Banners.  Here are the main differences:

• The chance of pulling a rate-up Operator when pulling a 6 Star Operator is 70% (instead of the normal 50%), with the result chance equally split between the 1 Limited Operator and 1 non-limited Operator.
• Previously released Limited Operators of the same Banner Series (more on this below) will be added to the non-rate-up pool after a certain amount of time has passed since that limited Operator's original release. This amount of time is determined based on the CN Operator release schedule, and is 1 year from the original release.  These limited Operators are 5 times more likely to be pulled from the pool of non-rate-up 6 stars (reminder that there is 30% possibility of pulling a non-rate up Operator when pulling a 6 star).
• Each Limited Banner has it's own pity count that is not shared with any other banner (standard or limited).  The pity count is lost when the banner ends.
• Each pull awards a  [Headhunting Data Contract].  300 can be used to purchase a 6 star from the relevant shop, 75 to purchase a 5 star.  The 6 stars available for purchase will be the 6 stars on the current banner plus any limited Operators the have been added to the non-rate-up pool (as described above in bullet 2)
• When the banner ends, any existing  [Headhunting Data Contract] will be converted into [Headhunting Parametric Models] at a 1:6 ratio.  At that point, they can no longer be used to hire Operators, but instead can be used to purchase development materials from the shop.  Details of the shop can be found here.

Arknights: Currency and Shop Guide

• The [New Year Celebration Lookback] Limited Banner is different than the others in that it doesn't have Limited Operators.  For these banners, the first (and only the first) 6* operator in this headhunting is guaranteed to be on of the Operators that the player does not currently have from a specified pool of existing non-limited 6 Stars.

Limited Banner Series'

• There are currently 4 Limited Banner Series: [Celebration], [Spring Festival], [Summer], and [New Year Celebration Lookback]. (Note that the Spring Festival, Summer, and New Year Series do not yet have EN translated names)
• Limited Operators are added to the non-rate-up 6 star pool of future banners of the same series after 1 year has passed (based on the CN Banner release schedule).  They also become available for purchase with [Headhunting Data Contract]s at the same time.
• The R6 Collab Banner Attack-Defence Tactical Collide with limited Operators was not announced to be part of any existing series, and it is unkown if this banner or these operators will ever be made available again in the future.
• The [New Year Celebration Lookback] Limited Banner is different than the others in that it doesn't have Limited Operators.  For these banners, the first (and only the first) 6* operator in this headhunting is guaranteed to be one of the Operators that the player does not currently have from a specified pool of existing non-limited 6 Stars.

Limited Operator and Series Lists

A list of all Limited Operators, their details, release dates, etc, can be viewed on our Operator List here.

Celebration Series Operators and Banners

Operators with wait period cleared on global (will show up on future series banners): W, Rosmontis.

Spring Festival Series Operators

All Operators in this series will appear on future banners of the series, since (until now) this series only happens once per year.

Summer Series Operators

New Year Celebration Lookback

Limited Banner Schedule

Based on the last year or so of CN schedule, it looks like there will be 4 regularly occurring Limited Banners per year.  There may also be additional non-regular limited banners (for example, the R6 collab banner)

Does Arknights rerun limited banners?

How long do limited banners last Arknights?

Does Arknights do reruns?

How do banners work in Arknights?