Is efficient to create my abstract class on C++ and the others on Blueprint?

I have 7 characters on my game, if i create a AbstracCharacter on c++ and make the other 7 on blueprints would be good? this is a good practice?

It depends how you design, main disadvantage is you can’t use C++ to specific characters or else you do some conditional code in base class. Personally i use Base Class C++, Blueprint extending my self as it easier for artist to operate them, if you use it think base class like framework which let you create anything from base system of your game.