Here's a list of magic items and some of their effects:

Item - Effect

Great Sword - +2 attack
Shield - +4 defense
Wand - +2 attack
Cross - +2 defense
Amulet - +2 defense, increased influence area
Warsong Big - + for attack and defense
Dragon Slayer Bigger -+ for attack
Evil Axe Enormous -+ for attack, big - for defense
Orb Magic - takes half as much energy