[Blue Archive] Grand Assault Nov 2025 - Hieronymus (Urban) Farmables Only + DPS Borrow

Hieronymus is not exactly the most noob friendly boss. The boss' mechanics will require you to have an invested healer, because:
healing the Green Relic to full HP will apply damage taken debuffs onto Hiero, up to 5 stacks
Hiero randomly curses one of your students, and you need to heal the cursed student to full HP to dispel the curse within 10 seconds, or she takes big damage

On top of that, Hiero also has a boatload of Defense. 2000 Def on Hardcore and 2900 Def on Extreme. Therefore, you will need to bring some Def Down students as well.

Now, let's see how far we can go with just farmable students + a good DPS borrow.

The rules of this clear are simple:
This clear needs to be replicable by every Sensei. Therefore, any student I use must be farmable, or must have farmable replacements
The only exception is Ako because I assume every newcomer rolls for Ako from Archive banner

The team I will be using across all 3 armor types are the same outside of the DPS borrow. The members are:
Tsubaki. She's there just to tank, nothing more. A well raised tank can take any hits from Hiero throughout the entire fight with little to no healing required (on Extreme and below), including the curses! Use your best tank
Akane and Maki. They are the Def Down students: Akane has EX Def Down and Maki has Basic Def Down. Good amounts of Def Down will help you get through this raid more reliably
Serina and Hanae. They will be in charge of healing the Green Relic as well as the Strikers

Speaking of the healers, it is highly recommended that you use burst healers instead of healers who heal over time like Hanae. This is because:
after healing the Green Relic to full HP, it applies the debuff to Hiero, stays full HP for a few seconds, then loses all its HP and gains a recovery boost debuff for 20 seconds. This means that with heal over time, you reach full HP slower, which means you gain and lose the recovery boost debuff slower
you only have 10 seconds to heal the cursed student to full HP before they take big damage. With heal over time, you might not be able to heal the student back to full HP within 10 seconds

Unfortunately, my Serina's healing is very weak, so I have to use Hanae to heal the Green Relic. However, I run into another problem: Hanae is so preoccupied with healing the Green Relic that I cannot use her to heal the Strikers, and she does not have healing in her Basic skill. That's where Serina comes in: although her healing is weak, she has just enough heals from both her EX and basic to keep the team alive, and that's all I need.

If your Serina is strong enough to be a solo healer in your team, you can bring Ako for Crit and CDmg buffs (and she also has healing in her Basic skill too!).

Now, let's look at each individual armor type.

For Elastic armor, I could not find any DPS that could clear Extreme with this team. Hanako Swimsuit and Nagusa both do not make the cut, and I don't have access to a Chiaki borrow to try. Maybe this would be possible if you run both Serina and Ako. Since I can't do it, I settled for a Hardcore clear. In Hardcore, I did not even need Serina, but whatever, imma keep the team consistent across all armor types. Team used:

Maki 1711 321 3* Lv73 (6)
Tsubaki 3474 485 UE30 Lv86 (14)
Akane 3113 874 4* Lv74 (13)
Hanako (Swimsuit) MMMM ??? UE50 Lv90 (A)

Serina 1111 223 3* Lv70 (13)
Hanae 3111 224 4* Lv70 (14)

For Light armor, I would like to showcase a less commonly used DPS option: Toki. Toki's EX ignores 60% of the enemy's Def, and has optimal mood in Urban, so she's a great option for this raid. You probably can get a similar clear with Hina Dress, but I decided to have some fun with this. Team used:

Akane 3113 874 4* Lv74 (13)
Toki MMMM ??? UE60 Lv90 (A)
Tsubaki 3474 485 UE30 Lv86 (14)
Maki 1711 321 3* Lv73 (6)

Serina 1111 223 3* Lv70 (13)
Hanae 3111 224 4* Lv70 (14)

For Heavy armor, there is literally no one better than Neru School for Urban Hiero. No other DPS even comes close. Neru School also comes with the bonus that she is pretty tanky, and can eat up a few curses like it's no big deal. Her EX also stacks more damage the more times you use it within a single Duel Time. Unfortunately, this team does not have the utilities needed to capitalize on that, but we'll see that in action in a future video. Team used:

Maki 1711 321 3* Lv73 (6)
Akane 3113 874 4* Lv74 (13)
Tsubaki 3474 485 UE30 Lv86 (14)
Neru (School) MMMM ??? UE50 Lv90 (A)

Serina 1111 223 3* Lv70 (13)
Hanae 3111 224 4* Lv70 (14)

Note that due to curse RNG, you may need a few resets to clear if your students end up dying

Timestamps:
0:00 - Hardcore Elastic (1:53.900; 7,562,656)
2:25 - Extreme Light (3:31.167; 15,039,919)
6:05 - Extreme Heavy (3:10.700; 15,069,392)