"Eye of Magnus" would be Miinsemagnus 'Eye of Magnus'. You could say Miinsekrein 'Eye of the Sun', but note that krein as meaning "Magnus" refers to the celestial object rather than the god "Magnus".

"Staff" is trickier since there's no direct translation for "staff", but you could say Zunsemagnus 'Weapon of Magnus' to capture that in very broad terms.