their are a lot of methods to defeat corvus. Here you get my party and how i defeated him

party: when your party is lv 50 or more you can defeat him easy

a mage

a gladiator ( better than warrior because of coup de grace but warrior is good to)

equiped : erdricks sword

a priest (for healing spells, make sure you have at last multiheal )

and at least a hunter

the special skills from your party at 100 points

and for the weapon also 100

you can do the quest a swindimples to get special skill books and for the hunter also where you've got your vocation from hunter.

the fight:you can use pschig up to raise strength ( do it to 100, great result)

for your mage you use the strongest spells you have

for the priest you can attack with abilities like multhitrust and thunder thrust ( spear)but you need to concentrate on healing to

for gladiator can use abilities like falcon slash

when you are min lv 50 this fight isn't that hard

ps heal before you fight thee first corvus ( after barbarus)

when you need more tips let a comment on this or my account i will answer as soon as possible