This is an Attack on Titan: What If? series that is basically the Attack on Titan anime but happens in an alternate universe where different things happen instead of how it's supposed to happen like in the original series. An example would be, what if Sakura Haruno from the Naruto anime were to completely replace the 60 meter tall Colossal Titan instead, scaling to the exact same size of 60 meters becoming the new "Colossal Sakura Titan"?