HOXY? EOD 1
I would say that this boss is significantly easier and faster than the plant. The mechanic is easy enough to maintain with Ksenia, G11, and KSVK.
V2 Klukai can finally see play, typically in the fire team granted that Springfield's bird will proc all 4 support attacks per turn by itself. The team can kill or close to it with either V2 Klukai or Ksenia in the filler slot.
The Hydro core can be shoehorned into any team and also come close to killing.
I saw a lot of people trying to recreate the wheel by forcing double Springfield+TLL. This is actually just terrible. You would rather borrow V6Springfield and use your own TLL over forcing a V1Springfield play. As such, I would recommend F2P either skip or grab V0Springfield as a dorm decoration. Unlike V2Klukai who can see play here for her 15% extra defense break, V1Springfield is a complete meme.
Ppsh getting shoehorn as a filler unit makes the boss stack +20%vulnerability per turn as opposed to +10%; it can push some near-kills into kills at about the same value of V2Klukai.
HOXY? will be recruiting 5 new members at the end of this gunsmoke since some members can't handle their McQueen failing 18% rainbow stamina training and are quitting to become better horsefags. Cutoff seems to be 12.7k/day.