If I am planning to make a game heavenly depending on character customization and I want it to work like the one seen in Aion: Slider to alter hight, weight, muscles and many more slider for face details. Is Unity the tool for me? Or must I look at more difficult to use Engines like UDK or CryEngine?
I know there is an example file with character customization for Unity but that is not the type of customization I am thinking of.
Unity is for you. Scripting is 5x harder in UDK/CryEngine. 
Unity’s ‘javascript’ is easy to learn and use. You can do anything with it.
I know, that is why I like Unity. But if Unity can not create the game I would like to make then it might not be for me.
It can make anything you want to make. You just have to put effort into scripting it.
You need to have a look at a morph and or modifier system both of which can be found in the MegaFiers system http://forum.unity3d.com/threads/89750-Mega-Fiers.-A-mesh-deformation-system-RELEASE from my chats with Chris I understand that he is using the system in his own game for doing a total Avatar system using Bulge for tummies and muscles and FFD for distorting faces as well as Morphs for more general changes such as male to female.
Im interested in the same sort of thing. Check out CP Morphing Lab…
Well i will just say this: if you use Cryengine it has already deep character custumisation included.