And while your statement about social, intelectual and physical characters is quite true, I'd like to run down what the games are actually about.

Vampire is an extended rape metaphor about inhuman undead creatures that treat humans as food and who have to live with the fact that they will lose their humanity and will end up turning on each other because there is nothing better to do.

Werewolf is about terrorists fighting a holy war and knowing they will mostly likely lose, but they are willing to die trying. The one thing that makes this palatable is that they know that their cause is objective, true and just.

Mage is a game about solipsist dreamers who seek to change all humanity into others solipsist dreamers so they could all redefine reality and Ascend into ultimate godhood.

Wraith is about loss, memory and things left unsaid. It's about crying over spilled milk and trying to cope with the last few things left after you in the real life while everyone around you tries to turn you into a psychotic killer or force you into endless wars that last for aeons.

Changling could be easily defined by claiming it is schisoprenic. The Changelings don't see the same world as everyone else, they see a clash of old dreams of lost Fae and our modern world. And with each day these echoes and wonders are lost a bit more because people don't care any more.

Kindred of the East is about being a horrible human being who was so bad in hell that it clawed its way out and got back to life. Now it seeks to become to ultimate immaculate demon serving its duty in heaven and become enligthened

Hunter is about playing the clueless idiot manipulated by forces beyond your ken and given powers to try and fight horrible things that go bump in the night and who only you can see.

If you take charaters from all these games and put them together, you either have to ignore the fact what the games are about, or you have to figure out who of them is wrong, thus devaluating the game itself.