I was thinking about all the thematics out and about all the champions i thought would compliment eachother really well in terms of a skin theme. And i thought hey.. Temptresses!
Top: Temptress Riven
Mid: Temptress Arhi
Bot: Temptress Miss Fortune
Sup: Temptress Leona
Jungle: Temptress Evelynn
Beautiful women clad in Black lace with an alluring gaze and a fiery lust in there hearts to doom all men! Beware their stare or Rest in Piece! 
nah not my cup of tea.
What about Temptress Garen
Riven and Leona don't fit very well
I am not against sexy skins but... skins in underwear just for the sake of being sexy? That goes a bit too far in my opinion then.
lol its just a basic idea in my head
Champs kinda fall into one of four categories IMO. The Just, the Intimidating, the Different, and the Teptress (for the purpose of this post)
The Just: these champs are sexy, but seem to fight for the good in a way that makes me doubt they would "stoop" to the level of tempting somone, such as Sona, Soraka, Nami, Lux (more justice oriented champions)
The Intimidating: these champs are sexy, but are so menacing to begin with that the mark would kind-of know the danger right away, such as Morgana, Shyvanna, Illaoi, Sejuani, Jinx, Vi, Evelyn (I put her here because I'm pretty sure I would be eyes wide open if a demon-looking creature was tempting me).
The Different: these champs are sexy, but different...such as Rek'sai, Poppy,
The Temptress: to me implies a lure-like hotness, but specifically with some hidden danger on the other side, such as: Cass, Zyra, Ahri (was a good choice), Sivir, Nidalee, Elise
Others? Annie (cause jail bait is dangerous :D ), Orianna or Camille (if you're Japanese, cause sex-bot :O )
