This is the strategy. First, lower physical defenses (impossible if Elemental defense since it uses +ed) till couldnt lower anymore with debilitate, Feebler or weaken (better if enchanted). Then attack with your physical damagers and you will defeat it.
Another way is to use the way similar to magicite overlord. Lower accuracy -40%. and then keep on attacking.
I know almost everyone knows this tips. But, for Beginners, you might need this tips. Well anyway, good luck of facing all elementums and Apollo Nox!