Polished Obsidian Stone of Darkness. Item Level 6. Cost: 250 GP

This large, gawdy silver band holds a large, round piece of polished obsidian stone.
First, it grants the wearer Darkvision.
Second, It allows the wielder to cast Darkness once per day per the spell’s description.

Void Blade Rapier. Item Level 11, Cost: 1,400

This +2 Striking Rapier has a black walnut handle, and it is trimmed in the finest gold with intricate carvings all around the hand guard. The blade is made of a strange star metal that appears jet black as night with green and yellow lightning rippling through it periodically.
When a spell is aimed directly at the sword’s wielder, they may raise the blade and make a special Reflex save against the spell caster’s DC in order to absorb the spell into the blade instead, rendering it harmless. Useable once per day.

Leather Armor of Obtenebration Item Level 13 Cost: 3,000 GP.

This +2 Leather Armor is black as night covered in specks that appear as stars on a mostly cloudy night. The darkness swirls all around the armor in an almost mesmerizing pattern. The armor grants +2 concealment bonus to Stealth rolls in darkness
Once per night, it allows the wearer to turn Invisible for 10 minutes as per the Invisibility Spell.