Artifacts are extremely powerful. Rather than merely another form of magic equipment, they are the sorts of legendary relics that whole campaigns can be based on. Each could be the center of a whole set of adventures—a quest to recover it, a fight against an opponent wielding it, a mission to cause its destruction, and so on.
Major artifacts are unique items—only one of each such item exists. These are the most potent of magic items, capable of altering the balance of a campaign. Unlike all other magic items, major artifacts are not easily destroyed. Each should have only a single, specific means of destruction.
Arcanis: Favoured by spellcasters, this +7 mithral longsword is an ornate weapon with a long, thin blade split down the middle. Possessing an improved version of the spell storing ability, a single targeted spell of any level may be stored into the blade. The wielder is automatically made aware of any spell that may already be stored when first obtained. The stored spell may be discharged on a successful, damaging attack as a free action. However, while a spell is stored, Arcanis provides the wielder with fast healing equal to the level of the spell stored (this effect does not stack with any fast healing the wielder may already possess). When making a successful attack of opportunity, the wielder is also healed by an amount equal to the level of the spell stored. When a stored spell is discharged, the healing effects of the weapon are suppressed, but another single, targeted spell may then be stored into it.
Brooch of the Hero King: Believed to have been first worn by a ruler of unsurmantable power and influence in days long past, this mithral brooch, in the shape of a many pointed star, enhances the wearer's leadership capabilities to epic proportions. The wearer's Leadership score is increased by 10 points, and he may command quadruple the number of followers normally allowed.
Synn: This adamantine blade is a terrible weapon forged with the blood of a vile god of destruction. To those innocent of heart, it is merely a +5 unholy longsword and inflicts an additional 2d4 negative levels with each strike, per an energy drain spell heightened to 18th level; to those who are of the most abhorrent evil, it becomes a +7 longsword of unholy power inflicting 16 negative levels to its victim with each wound via an intensified energy drain. Each negative level inflicted grants the wielder 5 temporary hit points. One day after being struck, the subject must make a Fortitude save (DC 38) for each negative level or lose a level. If the sword's power causes a character to have negative levels at least equal to his current level, the character is instantly slain and the wielder gains an additional 10 temporary hit points. Temporary hit points gained from this weapon last for a maximum of one hour.
On top of this, wielders who score a critical hit with this weapon rain down lightning from the heavens: each bolt is 5 feet wide and 30 feet long, striking any who stand 10 feet away from the wielder and inflicting 10d6 points of electricity damage upon them (or 120 points if wielded by an evil character). A successful Reflex save (DC 38) halves this damage.