Ginormo Sword

to beat necromancer, use a light elemented sword (enchant each sword with a different color, leave dark for energy blade (and the coin of bravery really helps here, avoids getting kicked out)

it's inside one of those temples (you know? those triangle-like map? lol, the one in the water map? well, these can't be entered until you beat up to....i think area 14-16

edit: oh, and keep upgrading with diamonds
the more you get, the stronger the sword becomes..
the actual sword level doesn't really do anything

but the amount enchanted does add up and makes it easier to kill things
i just tested no magic and only sword physical atk, i still 3 hit avatar without magic