[Blue Archive] Final Restriction Raid Nov/Dec 2025 - Fury of Set Light: Stage 55 Copium Clear

The Fury of Set is not an easy boss. In fact, it is widely regarded as one of the hardest bosses in the entire game. And Light Set is much more difficult than Special Set. Why is this boss hard, and why is Light Set harder?

To recap the basics (refer to    • [Blue Archive] Final Restriction Raid Nov/...   and    • [Blue Archive] Final Restriction Raid Nov/...   for more info):
Set has 80% EX Skill Damage reduction, so you need students who do damage from auto attacks (AA) or non-EX skills
Set has a lot of AoE nukes, most of them are damage over time
Set will periodically hit Obelisks with Hawk-Piercing Flash that has AoE damage and inflicts 70% Atk Down

The changes on Floor 50+ is that Set now deals Explosive damage

So, what makes Set difficult is that:
Your students need to have enough bulk to survive Set's attacks. You probably can still use Heavy armor Strikers for a while, but eventually you will need all Strikers to have Special or Elastic armor
You need strong AoE heal over time students to heal off the damage taken from Set's attacks. Hanako and Shigure Hot Spring are the most common choices for this
You need to rely on students who have strong AA, Basic and/or Sub skills

So, how does that make Light Set harder? Well:
Light Set has about 1.5x more HP than Special Set on all stages
We do not have an Explosive equivalent for Shiroko Terror
Most, if not all Explosive DPS that you normally use in raids are all EX damage students

With all these factors combined, they make Light Set one of the most dreaded and hated raid bosses of all time. A standard Light Set team on higher floors will look like this:
A main DPS. For Light Set, this will be Yoshimi Band
At least a secondary DPS. This is a common theme among all FRRs, where most teams will run 2 or more DPS on higher stages
A student with damaging EX skills to break red lightning spheres. More on that later
At least one AoE healer, ideally with heals over time. Hanako and Shigure Hot Spring are the most common choices
A single target (ST) healer who can heal the Obelisks. Kokona is by far the best option for Set, but you can also use Serina, Atsuko Swimsuit or even Hanae
Buffers. Yoshimi Band and your other DPS won't be able to clear this without buffers
Highly recommended: some form of Atk Down to reduce the damage done by Set
Optional: team repositioners, to move Strikers away from the debuff zone

Now, let's talk about the red lightning spheres. Set will periodically summon red lightning spheres throughout the fight. These red lightning spheres can only be targeted with EX skills, and deals damage to students near it. You will want to destroy this red lightning sphere, because when destroyed, it grants nearby students a 30% Damage Dealt buff for 35 seconds. This buff greatly improves your winning odds, and on higher stages, is necessary for you to even win this fight at all. And if this red lightning sphere reaches Set instead, then Set will get the buff instead, and we do not want that.

"But Assassin, EX skills don't deal much damage to Set!" Yes, they don't, so what you are looking for are students who deal good amounts of damage in their AA and/or non-EX skills who also have EX skills with damage. You will only ever use their EX on the red lightning spheres. And for that, there are 2 popular options:
Nonomi Swimsuit. She is by far the best option for Light Set, despite her terrible mood on Field. Her EX can destroy the red lightning sphere, and it also augments her AA to do more damage
Hina Dress. She actually has very solid AA damage, and has Elastic armor which works well for this fight. Many people will opt to use her instead because they have her raised

If you do not run a team repositioner, the Strikers' initial placement will greatly matter in this fight. This is because 2 of your 6 students will always have to take the damage debuff, regardless of which Obelisk you decide to heal up. The popular choice is to heal up the left Obelisk, because it gets targeted first so you don't need to heal any Obelisk before the first strike. This means that:
your damage dealing Strikers need to be in Positions 1-4 during team setup
your supports will take Positions 5-6

Then, during the fight, you will need to:
ensure that the right Obelisk never gets targeted by Hawk-Piercing Flash
heal up your Strikers through all the damage taken
remember to refresh Yoshimi Band's self buffs, but don't do it too often, her EX animation is extremely long
destroy every red lightning sphere that spawns

As you can see, with what I currently have, I can only clear Stage 55. At higher stages, I run into both survival and damage output issues. To advance further, I will need to raise my students further, so you will see them being stronger in later stages.

Detailed team info in pinned comment