Aqua and Seth (Violet) are very touhou coded in the chapter

Aqua gave me Koishi/Flandre vibes

Seth is very obviously taking heavy inspirations from Patchouli

TF2_Pyro said in comment #2610140:

Aqua gave me Koishi/Flandre vibes

She's like a fusion of remi and flan to me because of the uu~.

Shibi said in comment #2610157:

She's like a fusion of remi and flan to me because of the uu~.

It felt more Maria Umineko to me
Personally she felt more like if you took Suwako (you even hop on lilypads in one of her attacks) and gave her Flandre's personality