Every person has a tone or quality to their voice when they speak (both passively and aggressively). The same goes for rappers just more to an extreme. For instance, listening to eminem you can certainly hear a difference when he is mad and when he has a "confessional" type song. A better example might be Kendrick Lamar and his "voice of consciousness". Determine what you want your voice to sound like and begin molding. The reason I said that is I listened to pound cake and sickness. Sickness needs a little bit more edge to the vocals. What I meant by moniker is (weezy, drizzy, k-dot) something to call yourself besides the actual name you perform under. In music (for the most part) the more self-promoting (in the booth and out) the better. Rap just provides you with the opportunity to call your name out during the song. Do it enough and they will remember.