For this you need 3 items, the ring of iron fist (has efects of +25hand to hand and 33% reflect damage), the necklace of swords (+25blade and 33% reflect damage) and the shield you get from doing Pale Pass (or something) (it has reflect damage of 35% and is goldish brown and square).

Youu may use any other items with 33% reflect damage, but one must be 34% or more or there won't be pefect invulnerability.

When you get the items, put them on! No item amounts to making an attacker kill itself while you say "stop hiting yourself, stop hiting yourself..!"

Note: excuse me for the incorrect names, but they are as close as I could name them off memory.