A select group of magi are called to carry a black blade—a sentient weapon of often unknown and possibly unknowable purpose. These weapons become valuable tools and allies, as both the magus and weapon typically crave arcane power, but as a black blade becomes more aware, its true motivations manifest, and as does its ability to influence its wielder with its ever-increasing ego.
At 3rd level, the bladebound magus’ gains a powerful sentient weapon called a black blade, whose weapon type is chosen by the magus (see sidebar). A magus with this class feature cannot take the familiar magus arcana, and cannot have a familiar of any kind, even from another class.
Instead of the normal arcane pool amount, the bladebound magus’s arcane pool has a number of points equal to 1/3 his level (minimum 1) plus his Intelligence bonus.
A black blade is bonded to a particular magus, much like a familiar, but in more of a partnership than a master-servant relationship.
Intelligence: This is the intelligence score of the black blade. It starts at 10 and increases by 1 for every two levels of the bladebound magus (at 3rd level, 5th level, and so on).
Ego: A black blade starts with an ego of 5, and that ego increases as the blade becomes more powerful, as per Table: Black Blade Progression below. In cases where a wielder and the black blade come into conflict, like any intelligent item, a black blade can attempt to exert its dominance (see Intelligent Items). Due to its flexible and powerful nature, a black blade has a nonstandard ego progression.
Languages and Skills: A black blade starts with Common as a language. As the black blade increases in Intelligence, it manifests knowledge of languages and arcane lore. Upon reaching an Intelligence of 12, it gains a bonus language of the GM’s choice, and gains 1 rank in Knowledge (arcana). Each time the sword gains a bonus to Intelligence, it gains another language and another rank in Knowledge (arcana).
Senses: A black blade is aware of everything around it like a creature that can see and hear. It can be blinded and deafened as if it were a creature. It uses the saving throws of its magus, even if the magus is not currently wielding the black blade.
Black Blade Arcane Pool: A black blade has an arcane pool with a number of points equal to 1 + its Intelligence bonus.
A black blade has special abilities (or imparts abilities to its wielder) depending on the wielder’s magus level. The abilities are cumulative. A black blade normally refuses to use any of its abilities when wielded by anyone other than its magus, and acts as a masterwork weapon of its type.
Alertness (Ex): While a magus is wielding his black blade, he gains the Alertness feat.
Black Blade Strike (Sp): As a free action, the magus can spend a point from the black blade’s arcane pool to grant the black blade a +1 bonus on damage rolls for 1 minute. For every four levels beyond 1st, this ability gives the black blade another +1 on damage rolls.
Unbreakable (Ex): As long as it has at least 1 point in its arcane pool, a black blade is immune to the broken condition. If broken, the black blade is unconscious and powerless until repaired. If destroyed, the black blade can be reforged 1 week later through a special ritual that costs 200 gp per magus level. The ritual takes 24 hours to complete.
Energy Attunement (Su): At 5th level, as a free action, a magus can spend a point of his black blade’s arcane pool to have it deal one of the following types of damage instead of weapon damage: cold, electricity, or fire. He can spend 2 points from the black blade’s arcane pool to deal sonic or force damage instead of weapon damage. This effect lasts until the start of the magus’s next turn.
Teleport Blade (Sp): As a standard action, a magus of 9th level or higher can expend an arcane point from his or his black blade’s arcane pool, and can call his black blade from as far as 1 mile away, causing it to instantaneously teleport to his hand.
Transfer Arcana (Su): At 13th level, once per day, a magus can attempt to siphon points from his black blade’s arcane pool into his own arcane pool. Doing so takes a full-round action and the magus must succeed at a Will saving throw with a DC equal to the black blade’s ego. If the magus succeeds, he regains 1 point to his arcane pool for every 2 points he saps from his black blade. If he fails the saving throw, the magus becomes fatigued (but can try again). If he is fatigued, he becomes exhausted instead. He cannot use this ability if he is exhausted.
Spell Defense (Sp): A magus of 17th level or higher can expend an arcane point from his weapon’s arcane pool as a free action; he then gains SR equal to his black blade’s ego until the start of his next turn.
Life Drinker (Su): At 19th level, each time the magus kills a living creature with the black blade, he can pick one of the following effects: the black blade restores 2 points to its arcane pool; the black blade restores 1 point to its arcane pool and the magus restores 1 point to his arcane pool; the magus gains a number of temporary hit points equal to the black blade’s ego (these temporary hit points last until spent or 1 minute, whichever is shorter). The creature killed must have a number of Hit Dice equal to half the magus’s character level for this to occur.
Magus Arcana: The following magus arcana complement the bladebound magus archetype: arcane accuracy, broad study, dispelling strike, and reflection.