I believe that regardless of the actual position of the Sun in a Natal Chart, the Sun Sign alone carries energies of a particular House. It works like this: Since we are dealing with the Sun, the ruler of Leo, you start with a chart that has Leo Rising and then proceed to find the Sun in it. So let's say the Sun is in Pisces, that means it's also in 8th House. In a nutshell:
1. Leo Sun/First House: Masculine appearance, strong presence, assertiveness, leadership qualities, fearlessness, annoying up-in-your-face egotism, jealous one-upper behavior.
2. Virgo Sun/Second House: Money-conscious, builds and molds/fixes things slowly (painstakingly but well done and of good quality), attempts to validate self-worth (by being useful/helping others).
3. Libra Sun/Third House: Talkative, friendly, intellectual, charming, flirty, witty, cheerful, gossipy.
4. Scorpio Sun/Fourth House: Fiercely private and self-protective, sulks when upset, they have a small group of people they deeply care for, you don't really see many of them out there in the world (they keep a low profile instead).
5. Sagittarius Sun/Fifth House: Fun, happy, sunny, life of the party, stands out and possesses the "it" factor or star quality (Miley Cyrus, Taylor Swift, Britney Spears, Christina Aguilera, Nicki Minaj, Brad Pitt, you get the point), larger than life personality and self-expression, and they always steal everyone's thunder (sorry Leos).
6. Capricorn Sun/Sixth House: Hard-working, efficient, critical, responsible, practices till perfect, employs effective methods and routines (prefers tried ones of course; they're Caps after all).
7. Aquarius Sun/Seventh House: Stands out as "different" from everyone else (7th house rules projections, partnerships, open enemies ...basically others but yourself or what you think as yourself), oppositional, contrary, openly defiant, yet believes in equality (partnership is about equality), is also friendly and social, and hates injustice (social injustice that is).
8. Pisces Sun/8th House: Saint or sinner/angel or demon (mostly demon though), enigmatic personality, psychic, mysterious, tortured/tormented soul (addict or artist), devious, slick, manipulative, sadistic, and in some cases plain cruel and cold-blooded (you don't usually get this qualities with other Pisces placements).