Heretic, and are used to open their respective doors throughout various levels.
There are three different types of keys in the game - Yellow, Green, and Blue. All three keys are not always used in every level (mostly the earlier ones in each episode), but they are always found and used in that order.
|Heretic - Weapons & Artifacts|
|Weapons||Staff • Gauntlets of the Necromancer • Elven Wand • Ethereal Crossbow • Dragon Claw • Hellstaff • Phoenix Rod • Firemace|
|Ammunition|| Wand Crystal • Crystal Geode • Ethereal Arrows • Quiver of Ethereal Arrows • Claw Orb • Energy Orb •|
Lesser Runes • Greater Runes • Flame Orb • Inferno Orb • Mace Spheres • Pile of Mace Spheres
|Healing||Crystal Vial • Quartz Flask • Mystic Urn|
|Armor||Silver Shield • Enchanted Shield|
|Artifacts|| Keys • Torch • Map Scroll • Bag of Holding • Shadowsphere • Tome of Power • Ring of Invulnerability •|
Wings of Wrath • Chaos Device • Morph Ovum • Time Bomb of the Ancients