Not without scripts or plugins. You haven't even mentioned what engine you're using. There are Support forums for each of the engines, as well as Script and Plugin Requests forums (and Script and Plugin forums where you can search for something already existing). Those are where you should post to get help with your game.
Edit: Actually, if you're using MV, create a battle spritesheet using any character (use the character generator and just generate one). Then edit it in your image editing program and replace each sprite in the image with the picture you want to use instead. Of course it won't be animated, and you might find some lining up issues with the weapons used for the battle animations.