WillowBuild and Guide

Willow is a 6-star Arcanist of the Plant Afflatus. She is the second cornerstone of the Poison team, using her unique [Poison] adjacent debuff, she destroys any long-form content. Note that she gets significantly weaker if not paired with Tuesday.

Her kit revolves around the [Hag's Bane] debuff. This is a debuff that stacks on itself (think of the [Burn] debuff) and is considered [Poison]. At the end of the round, it increases its own DMG Dealt based on how often it's triggered per round (up to 4 times per round, max 10 stacks). Of course, Willow has ways of triggering this debuff more than once per round.

Let's start with how she generates [Hag's Bane]. For this she uses "Hag's Advice", which converts existing stacks of [Poison] into [Hag's Bane]. To do this you need sources of [Poison] such as Tuesday or Sotheby, as the only way Willow can generate [Poison] is with her Insight 1.

On the other hand we have "Hag's Gratitude", which consumes [Poison] stacks and triggers [Hag's Bane] 1 time (to work towards the goal of triggering its multiple times per round).

Her Ultimate "In The Fire, In The Shadow" is the most important part of her kit. It enters her into the [Ancient Ritual] channel. While active, [Hag's Bane] is considered to have triggered an amount of times per round even if it hasn't. In addition, to keep the channel active, Willow consumes around 4+ Moxie per round and inflicts [Hag's Bane] on all enemies equal to the consumed amount of Moxie. If not enough Moxie is available to consume, the channel ends and she casts “Ending Pose” which is a mass attack that scales its damage with the amount of [Hag's Bane] on the target.

Gameplay

Willow pushes [Poison] into a meta position, with a caveat.

If you don't have Tuesday, don't even bother playing Willow. Without the combo, Willow's damage drops so dramatically she gets beaten out by Jessica.

Outside of that, there's a lot to unpack. Right off the bat, [Hag's Bane] has a great modifier, layers on itself, and an insane modifier once the triggers are fully stacked. This is easy to do if you keep [Ancient Ritual] active, which is the primary gimmick and problem surrounding her kit. The longer you keep it active, the stronger you make [Hag's Bane] and the harder “Ending Pose” will hit; do it wrong (i.e. ending early or miss timing it) and your damage plummets.

Do it right and you're hitting your enemies with ATK*50% Genesis DMG (per stack of [Hag's Bane]). As you'll be running, on average, 7 or more stacks, it'll be stacking quite considerably.

This is ALL under the presumption that Tuesday is present in your team. The “Ending Pose” cast is potentially strong, but a majority of the damage output is tied to the [Hag's Bane] triggers per round. As it is considered [Poison], it cannot normally Crit. To help this, Tuesday has an effect called [Fear's Cradle] that allows [Poison] to Crit, which also affects [Hag's Bane]. This is one of the main reasons that Willow without Tuesday is almost non-functional.

The downside to this is [Ancient Ritual]. Willow's Insight 3 makes it so that she gains extra Moxie while in the channel, meaning that you'll need to dedicate at least 2 AP per round to casting/merging with her in order to upkeep it. Tuesday helps a little with [Room Service] allowing you to overcap on Moxie, but she brings the problem of needing to upkeep her Array, which makes you required to dedicate 1-2 AP per round to casting/merging with her. This gives VERY little room for other units to act, forcing you into picking units with a relatively AP-positive playstyle.