can riot games champion designers create a champ that uses illusions ?

i thought about some champion that uses illusion magic and change from offensive kit to defensive kit using their ult because there is no champion like that in the game and i was just curious about it (and please not like shen his illusion 'ki sword' is pretty bad he looks like low tier illusioner) btw the type of illusion i mean is not creating other clone or polymorphing i mean creating something optical that doesn't exist like shen's sword