I agree with soren. 
You can use it. But don't be able to become a full on titan at first. 
Titan-ize parts of your body in the beginning and as the story goes on then you can grow stronger. 
Like my character will do basic dragon slayer techniques. (as in based of existing ones like roar, punch, etc.)
However, the more advanced techniques will either be very taxing, one use only, or unusable.

EDIT: Heh... Cooper got genderbent XD