What is the Lingering Glow archetype?
This archetype revolves around the generation of [Lingering Glow] stacks. To do this, simply apply the [Burn] or [Halo] debuff. These are both damage over time debuffs that reduce incoming healing, deal damage and whose stack count gets cut in half at the end of the round (forcing you to stack them frequently).
Like the debuff that generates it, [Lingering Glow] constantly reduces itself at round’s end, and naturally most characters belonging to the archetype perform at their best when it’s at a high stack count. This makes it important to keep generating stacks of [Lingering Glow] despite how fast it and the [Burn]/[Halo] debuffs fall off. Thus the archetype favors a high frequency of outgoing attacks and casts to prevent [Lingering Glow] from dropping too low, which also makes it a prolific enjoyer of things such as AP+ buffs, AP-less casts and long duration buffs.
How to play Lingering Glow?
Its core gameplay loop is ridiculously simple, trying to even out bouncing between high and low stacks of [Lingering Glow]. This translates to: “cast a lot”. That’s really all you need to know.
At its foundation, the archetype is just asking you to inflict [Burn]/[Halo] as often as you can. Most Lingering Glow characters (especially Supports) also have the tendency to increase the maximum stack count of these debuffs, creating bigger swings in stacks if you are not paying attention. Not having the requisite [Lingering Glow] stacks that your team needs every round will neck your damage fatally as almost everything scales with it. However, since every character belonging to the archetype inflicts these debuffs with basically every action, it's also not very difficult to keep uptime on.
In Depth: What prevents you from going entirely brain-off in Lingering Glow as it is currently, is when Beryl is helming the team.
Beryl wants to cast her Ultimate every two rounds to re-distribute stacks of [Halo] across all enemies. This counts as ‘inflicting’ the debuff, and is thus a large source of [Lingering Glow] generation at the same time.
This means that you want to cast at least 2 of her Basic Incantations per round, also on rounds where she is casting her Ultimate, due to this she is one greedy unit in terms of AP. Her basics are best cast at the tail end of the AP Area, as her S1 will inflict extra [Halo] based on its total stack count on hit. At the same time you want to cast S2 as many times as you can early on during stages to ensure a smooth upwards curve of [Vision] stacks. Small optimizations and rotational awareness, such as utilizing Lorentz Butterfly’s copy to supplement your early S2 casts and alternating Beryl and Lorentz’ Ultimates will help you hit your damage ceiling faster and stay there.
But what are the benefits to playing Lingering Glow over other Archetypes, and what may make you reconsider?
Access to an incredible amount of active casts. With the Best In Slot roster, it’s not uncommon to see anywhere between 5-8 cards in the AP Area roughly every round if you’re playing it well.
Incredibly high burst DMG output when the [Lingering Glow] stacks and supportive set-up are timed just right.
CAN viably substitute half of the team with other options, especially the sustain slot, which helps make the archetype somewhat accessible. You technically need only one [Lingering Glow] character in the team for [Burn] to generate stacks, so generic [Burn] appliers like
J can be used as well.
At the time of writing this: The best optimization of the team and its rotation is very strict. The optimal team is quite premium (a mandatory Limited unit) and the strict rotation gives the archetype a very inflexible ceiling.
The team is essentially a ‘glass cannon’, sporting several remarkably fragile units that have a high chance of randomly getting one shot in endgame content (especially Beryl).
While currently not prevalent, the archetype gets hard-countered by enemies that are able to cleanse or those that are immune to debuffs.
Teambuilding
At the time of writing this, Lingering Glow is on the stricter side of its teambuilding. Being a newer archetype, it hasn’t had much time to establish a very flexible roster beyond the team that ‘works’, so this section will hopefully be updated to be more expansive in the future.
Currently, your BIS will be:
Beryl / 
Isolde / 
Lorentz Butterfly / 
Marsha
Spathodea is usable, but isn’t nearly as strong as Beryl and focuses more on single target damage. In terms of gameplay needs, she is identical to Beryl, though the optimizations are a bit more flexible.
Flexing out Lorentz Butterfly doesn’t damage the team’s integrity as much as one might assume, leaving room for other Supports so long as they can adhere to the team’s general wants (detailed below).
When looking at future releases for this archetype, especially if it’s not a Damage Dealer vying for Beryl’s spot, make sure you are looking for the following things:
Are they like Isolde in that they can provide most of the offensive buffing and support while remaining close to (if not completely) AFK? This is important as [Lingering Glow] damage dealers are quite AP-.
Are they like Lorentz Butterfly in that they can grant extra AP or circumvent the action economy in other ways (copy, ap-free states, auto casts)?
Can they inflict a lot of [Burn]/[Halo] and/or increase the maximum stack counts of these debuffs so that more can be inflicted in one go?
If a character doesn’t have at least two of these qualities, they will be difficult to utilize fully in this team. However, if they have one of the options and are just ridiculously good at providing offensive support for your current Damage Dealer (say, 
Flutterpage for Beryl) the option is there.
Unit ranking
What follows are two tables, one displaying only characters that adhere specifically to the Lingering Glow Archetype. The other is a table of Generalist options, also ranked. Take note of the following:
Core — Integral to the functionality of the archetype.
Common — Most often seen in this position alongside the Core. Can be BiS.
Flex — Either good in specific situations or potentially good in a Common slot.
Cope — Only really used if nothing else is available. And even then, lmao.
Lingering Glow Unit Spread
Damage Dealer | Support | Sustain | |
|---|---|---|---|
Core | | | |
Common | | | |
Flex |  | ||
Cope |
Core:
Isolde (E1) – Integral [Burn] supplier, AP+ (de)buffer with high Mass output over the course of a stage.
Marsha – AFK shield support with Lingering Glow synergy. Also defensive buffing to help nullify some of the team's squishiness.
Common:
Beryl – Primary (and only) [Halo] supplier with extremely high Mass output and lots of Follow-Up Attacks.
Lorentz Butterfly – Versatile AP+ support with Moxie generation, AFK offensive buffing and card copying.
Flex:
Spathodea (E1) – Generically strong DPS with high ST output. Similar playstyle to Beryl.
Cope:
N/A
Generalist Unit Spread
Damage Dealer | Support | Sustain | |
|---|---|---|---|
Core | |||
Common |  | | |
Flex |  | ||
Cope |  |  |
Core:
N/A
Common:
Rhiannon – Extremely versatile buffer with AP-free gameplay that can remove of a lot of the more technical aspects of the team.
Flutterpage – Ridiculously powerful FUA buffer specifically for Beryl. Wins out over Lorentz Butterfly if you only have Portraits on Beryl.
Flex:
Fatutu – General healer sustain with powerful FUA debuffs. May struggle due to the team's low defensive stats and being a healer.
Cope:
Lopera (E1) – AP+ Incan & Ult Might buffer with small [Burn] synergy. Not the best choice, also not the worst. Her healing can also help make the team less vulnerable.
Kiperina – Generically good AFK shield sustain with offensive buffs.