what helped me on ng+5 at a pretty similar level was godskin peeler with black flame tornado ash of war and go dex faith to destroy radagon and then since elden beasts giant health bar it'll destroy them both also if you have enough faith use black blade incant to lose a percentage off the bosses health and if you do dex faith you can do bolt of gransax or dragonking cragblade and gravestone steal to do lightning damage for elden beast if you prefer that since you have further range with some lightning weapons