Darkstone boots

Darkstone boots are the most powerful boots in RuneScape. They are the opposite counterparts of the lightstone boots. They are obtained after completing the quests While Guthix Sleeps, Nomad's Requiem, Void Stares Back, and the new grandmaster quest Isle of Zaros.

After the Isle of Zaros, speak to The Enlightment about caskets, and he will say you need 3 quests required to open these caskets, which cost 500,000 coins each from him. The boots are 1/50 chance of receiving, when you find the casket with the boots it will come up with a description which you will choose which ones to take.

During the Isle of Zaros, Commander Kaylin wears the darkstone boots and Commander Tara wears the lightstone boots, during the final fight, you will need to defeat Commander Kaylin (level 650). After the fight he will transform into a level 1039 Zamorak Commondora. Defeat it with Kaylin and you will see their boots falling into the sea, causing them to be locked in magical caskets. Kaylin then gets a new pair of boots (Fusion boots, obtained if you give both pairs of boots to Kaylin).