Drag your character's file (fbx, cd3, etc.) into the Unity folder you just made. All of your character's elements will be imported into the same file, including materials.
Create a new project called "Rigify Test" in Unity. Simply drag and drop your model into the project window once it is open. In the project window, select the model's prefab and then click Rig in the inspector. Click Configure and change the Animation Type to Humanoid. All of the bones should now work together to form Mecanim.
Unity is a game engine, so it's better at handling animation than Blender, which is a 3D graphics programme. While Blender does support bones, IK rigging, and even motion capture for animation, Unity is powerful enough to take all of these and produce complicated animation.
A character design is a process that requires careful consideration of the visual appearance, personality, and backstory of a character. The process can be broken down into three main steps: 1) Conceptualizing the Character 2) Designing the Character 3) Building the Character.