Fairy or Clandestine (妖精か内密, Yōsei ka Naimitsu)

Just practicing some of my Japanese.

Plus, I'm trying to debate on the next story I should write. Should it be about Fairies (Yōsei)? or Clandestine a.k.a. a Secrecy Clan (Naimitsu)? I can't decide at the moment.

Here the titles to choose from:

01. Fairy Charm (Cubex-21)*
02. Clandestine
03. Lantern Fairy
04. FairyxLantern

*it's like a algebra thing. Cube means Square (or Sq.root), X is the unknown number and 21 is a minus number.