There was no Leonardo the Magnificent. Lorenzo de Medici was known as Lorenzo the Magnificent.
Siamo magnifici
Magnifique is a French equivalent of 'magnificent'. It's the same form regardless of whether the 'magnificent' object or person is feminine or masculine. It's pronounced 'mah-nyee-feek'.
Magnifico is the proper Latin word that explains the English word magnificent.
In the fairytale the kings castle was magnificent