minimum advice is change the +5k Weapon damage on Skullshield to Epic +100% Weapon dmg if you want it to do more damage or +20% Fire dmg if you want more damage for both weapons. you can change Wizardry Talent to Amplify to get +40% damage to enemies with Fire DoT on them. you have +48.8% Elem. Crit. on the Staff which should be enough. also, do you have a Hell Slime with Demonic Set?
if you want to do lots of changes you will have to get the Legend versions of these Items as only about 6 Crystals can be used on Eternal Items.