I hate to say this, but Rick Riordan has not invented a character that Leo could be with. They are all to serious. I hope that Rick will make someone for Leo in the Weiter two books, and possibly one for Nico.
If Thalia was a option the would have the most B.a.m.f kids ever. Sorry, two of my Favorit character's. Fusing them with be like Greek feuer molotov's, infinitely kickass
I'm sorry people but I think Frank's gonna die. Think about it: It keeps saying in the Bücher that his life's gonna burn short and bright, so I think Leo's gonna end up with Hazel.