Abyss: Floor 83 (Scorpetra): BEATEN!
■ Team Comp:
• Arkasus (guardian)
• Armin  (6* Awakened; S3 +2; 37,268 CP; 1839 DEF; 9013 HP; 144 SPD; 20% EFF, 29.0% ER; 5.4% MI; Aurius @15)
• Angelica  (6* Awakened; S3 +3; 32,981 CP; 1029 DEF; 15,004 HP; 144 SPD; 21.0% ER; 5.4% MI; Celestine @15)
• Schuri  (5* Awakened; S2 +5, S3 +3; 42,168 CP; 709 DEF; 9572 HP; 195 SPD; 1339, 100.0%, 153.0%, 19.0% EFF, 13.0% ER; +6 MI; Sashe Ithanes @15)
• Cidd  (6* Awakened; S1 +5, S2 +5, S3 +5; 73,215 CP; 146 SPD; 3323, 90.0%, 253.0%, 28.0% EFF, 5.0% ER; No MI; Daydream Joker @30)
For the first wave, the goal was to come out with everyone's skill ready (except Armin, hopefully he'll be the first to get stunned) and max soul charges.
Due to the the fight mechanics, in order to achieve this, I used everyone's skills only when needed and slowed my dps as necessary.
When the mini-boss was around 30% health, I stopped using Angelica's S3 then started using Armin's S3 (soul-burned) to mitigate damage from the mini-boss' ultimate skill.
□ SECOND WAVE IMPORTANT DETAILS:
I never soul-burn Angelica's S3 so I can replenish soul charges a.s.a.p..
The boss gains a stack of speed & attack AFTER EACH TIME SHE TAKES A TURN. You can not sit on this boss trying to build souls or wait for an opportuny because she'll become too fast/strong and overwhelm you. Also, if you don't keep her debuffed, she'll gain a barrier at the end of her turn.
@rundat6 [STOVE91150006] informed me that when a minion is killed, it respawns with the percentage of combat readiness it had when it was defeated, so, it's best to kill any minion when its combat readiness is as close to 0% as possible.
▪︎For the second wave, unfortunately there is no real strategy to recommend due to battle's RNG fight mechanics (heroes are randomly stunned by her skill 'Curse Beam' and attacked by her skill 'Destruction').
You take "the cards you're dealt" and manage them the best you can.
Save Arky to kill the yellow crystal when your dps can't (hopefully RNG will be in your favor in that you won't run out of soul charges and need to use Arky).
In my case, at second wave start, my single-target dps got stunned, so, I had to sit there for who knows how long attacking the yellow crystal with my non-dps heroes until it's health was low enough that an Arky 'Lightning Smash' would kill it (side note, I tried to demonstrate what I did at the end when I knew I had the win).
Once my single-target dps was no longer stun impaired, I recovered some health and got the boss debuffed.
When I realized I might still have a chance, I started recording.
Arkasus is great as steady dps when your team doesn't have outstanding damage. In this fight, he was key in surpressing the respawned minion especially when my single-target dps could not kill it before it took a turn.
Armin was a big help (though any knight with Aurius will fit the bill of soaking damage). His S3 brought heals & a barrier which allowed me to sparingly use/supplement Angelica's S3. His S2 brought debuff 'poison' which helped kill the yellow crystal, the boss, and helped keep the boss from gaining a barrier at the end of her turn.
Angelica (besides healing) gave buffs 'immunity' & 'barrier'. This kept my team from having their combat readiness reduced when the boss used skill 'Flash Beam' and from being stricken by other debuffs.
Schuri was more beneficial than I realized (thanks to @rundat6 [STOVE91150006] for suggesting I use a combat readiness manipulator). Not only did he help keep my team ahead of the boss (reducing how often I had to experience the RNG fight mechanics), he also too brought debuff 'poison' which aided in killing the yellow crystal, the boss, and helping keep the boss from gaining a barrier at then of her turn.
Cidd is my all-star. When he has buff 'increased speed' (self-applied whenever his S1 crits), his S1 applies debuff 'decreased defense' on hit and his S3 uses an advantageous element (the Cidd doesn't care what your element is)! Wombo-Combo! He was key in killing the respawned yellow crystal, keeping the boss debuffed so she wouldn't gain a barrier at the end of the turn, and dps'ing the boss down.
Hope this helps!