[Touhou LostWord] vs Advanced Challenge - Purple Heart Only Clear - ▾42 SP, 7 Turn - (

Combat at 0:00. Character set-up at 4:31.
This challenge is pretty hard... It took a few hours to work out a comp for this and optimize it at least a bit. I even had to let Lady Kaguya obtain full power just to clear this stage. Even then, this comp feels a bit long and a bit costly to me. Oh well.
This can probably farm at Pink Heart at 42 SP. Maybe with enhanced agility on Mima. Or just don't debrick so that your comp can win despite Suwako cursing you.
☆☆ Character Set-Up ☆☆
[C3 Yuyuko] 》-----《 [LM1 Mima]
[F1 Koishi] 》-----《 [L80 Kaguya]
[L80 Yuyuko] 》-----《 [L80 Kasen]
C3 Yuyuko - 5* MLB - Purple Heart, Rank 4 - Yang ATK +100
F1 Koishi - 5* MLB - Purple Heart, Rank 4 - Yang ATK & DEF +100
L80 Yuyuko - 1* LB0 - Purple Heart, Rank 4
LM1 Mima - 5* MLB - Purple Heart, Rank 4 - Yin ATK+100
L80 Kaguya - 1* MLB - Purple Heart, Rank 4 - Yin ATK & DEF +100
L80 Kasen - 1* LB0 - Purple Heart, Rank 4
☆☆ Story Cards ☆☆
C3 Yuyuko - Magician's Broom, Yang Slice*, Yang Slice*, Yang Slice*, Gaze Upon the Flowers
F1 Koishi - Yang Hard*, Yang Hard*, Yang Hard*, Dancer in the Puddle, LSaS
L80 Yuyuko - n/a, Bibliophile on Duty
LM1 Mima - Yin Slice*, SHTTU, Yin Slice*, SHTTU, ESP
L80 Kaguya - Destructive Order, Yin Hard*, SHTTU, Yin Hard*, Infinity Garden
L80 Kasen - n/a, Myouren Anni
Notes:
~ Destructive Order is a recent event card.
~ Bibliophile on Duty is obtained from the buddy system.
~ Yang Slice = Yang ATK + Agility stat stick
~ Yang Hard = Yang ATK + Yang DEF stat stick
~ Yin Slice = Yin ATK + Agility stat stick
~ Yin Hard = Yin ATK + Yin DEF stat stick
☆☆☆ Overview of Strat ☆☆☆
T1: Full Break Enemies
T2: Kasen buffs nukers, Koishi nukes gauge 1
T3: Full Break Enemies
T4: C3 Yuyuko nukes gauge 2
T5: Debuff Enemies
T6: Debuff Enemies
T7: Kaguya & Mima nuke together
☆☆☆ Strat ☆☆☆
Turn 1:
(L80 Yuyuko uses skills 1-3, swap out L80 Yuyuko)
C3 Yuyuko - Spread Shot
F1 Koishi - Use skills 1-2, 2p SC4
L80 Kasen - Use skill 2, Focus Shot
✣ All Enemies Full Broken ✣
Turn 2:
C3 Yuyuko - Spread Shot
F1 Koishi - Use skill 3, 3p LW
L80 Kasen - Use skill 3, Focus Shot
✣ Gauge 1 Broken ✣
Turn 3:
C3 Yuyuko - Use skills 1-2-3, 3p SC1
F1 Koishi - 3p Spread Shot on Sanae
L80 Kasen - Use skill 1, 3p SC2
✣ All Enemies Full Broken ✣
Turn 4:
C3 Yuyuko - 3p LW
F1 Koishi - Spread Shot
L80 Kasen - Focus Shot
✣ Gauge 2 Full Broken ✣
Turn 5:
(F1 Koishi uses skills 2-3, then swap out C3 Yuyuko & F1 Koishi in that order.)
LM1 Mima - Graze thrice, SC2 on Sanae
L80 Kaguya - Graze thrice, use skills 1-2, SC3 (with SHTTU) on Sanae
L80 Kasen - Graze thrice, use skill 2, 3p Focus Shot
Turn 6:
(Swap out Kasen)
LM1 Mima - Graze thrice, use skill 3, 1p SC4 on Sanae
L80 Kaguya - Graze thrice, use skill 3, 3p SC1 on Suwako
L80 Yuyuko - Graze thrice, 2p SC2 on Sanae
✣ 96% chance Suwako gets stunned here, otherwise good luck with -7 Party Crit ATK/Crit Acc ✣
Turn 7:
LM1 Mima - Use skills 1-2, 3p LW
L80 Kaguya - Graze once, 3p LW
L80 Yuyuko - 3p Spread Shot
✣ Battle End ✣
Duration: around ~2:34