Amulet of the Astral Dreadnaught

Source: Ethan’s Homebrew

Wondrous item

The wearer of this amulet has a 1 in 6 chance to reflect any magic damage back toward the caster.

Note that reflecting the damage does not negate the damage - the wearer still takes the damage, but so does the caster.

Once per day, the wearer can use the amulet to negate the damage of one magical attack.