The names of the bosses of the other two themes in Hidden Summoners are revealed!
麗の魔妖-妖狐 Uruwashi no Mayakashi – Youko (Beautiful Mayakashi – Youko)
“Ah, how unfortunate. The flames of our ghostly realm will soon snuff out any insolent flickers…”
TL note: “Mayakashi”, using the kanji for “magic/evil” and the “bewitching” kanji from “youkai”, is a play on the “ma” reading of the “magic” kanji and the word “ayakashi”, another word essentially meaning “apparition/youkai”
When written without kanji, “mayakashi” means “fake/phony/deception”
Youko may be a name here, depending on the other members, but it is also the word used to describe fox spirits/“kitsune”
プランキッズ・ハウスバトラー Purankizzu Hausubatoraa (Prankids/Planckids Housebattler/Housebutler)
“Another tumultuous day at the Prankids House!”
The theme name here is Purankizzu, which is likely either Prankids or Planckids (get it they’re small)
Also, as to Nephthys’ tagline is:
Thanks to Decchan for the explanations.