After messing with model position and rotation for 3 days, I got this thing to work. It replaces the throwing knife with a shuriken. It includes a golden, black, silver, and iron texture.

Note to modders: The offset of the model is determined by the distance from the 0X 0Y 0Z position in Blender, at least in FBX. I have no idea about other formats. Also remember to check the real size of the model in UE4 by checking the asset´s attributes and import it with the correct scale, since Blender makes a model that´s usually 100 times bigger than the real asset.