Syntithenai

Synopsis
Syntithenai is a magical artifact that the party recovered on the island of Ymana.

Physical Description
The hilt and pommel of the sword are a deep emerald green color, inlaid with small diamonds and emeralds.

The blade of the sword is banded and mottled like damascus steel. One face of the blade is engraved with eight circles, each about the size of a quarter. As the party has attuned to the sword, the circles have illuminated with the following magical inscriptions:


 * Frog: A five-pointed golden star.
 * Gragnok: A glowing white shield.
 * Patches: A candle matching his holy symbol.
 * Jack: A swirling vortex of the four elements.
 * Rye: A "ying-yang" of radiance and light, and fire and darkness, with a music staff between.
 * Malkoth: A symbol matching his infernal amulet.
 * Odell: The arcane sigil for binding / connecting, which is common to all rune magic (as well as conjuration and transmutation magic).
 * XVIII: A skull with blood dripping from its jaws.

History
Syntithenai was forged in the late years of the Age of Arcana, by an ambitious and somewhat imprudent mage named Folenor Joris. Like some other powerful mages during his time, Folenor aimed to kill one of the gods and ascend to take their place. Specifically, Folenor sought to replace Asmodeus, the lord of the Nine Hells.

Folenor forged Syntithenai using Material Chaos - a feat that had not been performed before or since. The sword was designed to gain power from those who wielded it, imbuing itself with the strengths of its bearers. To this end, Folenor traveled around Materi with the sword and visited some of the world's most powerful mages, in the hopes of imbuing Syntithenai with all of their strengths. He eventually convinced seven other mages to attune to the blade and awaken its powers: Tamrius Grimm, Passeri, Myriostoma, Avara Wasanthi, Alusfaen Orion, Daimao, and Basel Anselmo.

With the blade fully awakened, Folenor traveled to Chwaka to do battle with the forces of Asmodeus, and was never heard from again.

General Properties
On its own, Syntithenai functions as a +1 magical longsword, with no additional properties, which requires attunement. It gains additional properties based on who is currently attuned to it, as described below.

By studying the sword and using multiple castings of identify, the party has discerned that the sword was designed to gain power from those who wield it, imbuing itself with the strengths of its bearers. It is fueled by synchronicity, and draws its magical power by melding the strengths of those who wield it. As such, it benefits from changing hands often, and can lose some of its power if it is wielded by the same person for too long. Over time, the party discovered that the blade had additional properties that could be unlocked by repeatedly utilizing the blade. They have since unlocked all such properties, and fully awakened the blade.

Charges
Some of the blade's features include charges. The blade retains the same percentage of its remaining charges, rounded down, for all such features. (for example, if the blade's exalted Diplomatic Immunity property is active and has 1 remaining charge, and its exalted Sorcerous Intervention property becomes active, the Sorcerous Intervention property has only 1 remaining charge).

Power Balance
The blade is fueled by synchronicity, and draws its magical power by melding the strengths of those who wield it. As such, it must change hands often in order to retain its power. Consistent overuse by the same individual causes its power to become imbalanced, and eventually to break. This is represented by the following mechanics.

At the end of each short rest, if the creature that is currently attuned to the blade has awakened the blade, that creature gains an Imbalance Point (to a maximum of 3 points). In addition, at the end of each short rest, any creature that is not attuned to the blade loses an Imbalance Point (to a minimum of 0 points), provided that another creature is attuned to the blade. If no creature is attuned to the blade, no creatures gain or lose Imbalance Points.

When a creature accumulates 3 Imbalance Points, their symbol on the blade shatters. While a creature’s symbol on the blade is shattered, if they attune to the blade, it functions as a +1 magical longsword with no other magical properties. A shattered symbol on the blade returns to normal when the corresponding creature has 0 Imbalance Points.

If all of the symbols on the blade are ever shattered at the same time, it reverts to its dormant state and must be reawakened.

Frog Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon.

Diplomatic Immunity. The blade has 3 charges. While you are wielding the blade, when a creature within 30 feet of you that you can see, other than yourself, is subjected to an effect that allows them to make a saving throw to take only half damage, you can use your reaction and expend one charge from the blade after the creature makes their saving throw, whether they succeed or fail. If the creature failed their saving throw, they take only half damage. If they succeeded, they take no damage. Once you use this feature, you cannot use it again until you complete a short rest.

The blade regains all expended charges at the end of each long rest. If the blade does not have any remaining charges, you can spend uses of your bardic inspiration feature instead to activate the blade's properties.

Team Skill
After Frog awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Leap Frog. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When you give a bardic inspiration die to your attuned ally, you can choose to disappear in a twinkle of starlight and teleport to an unoccupied space of your choice adjacent to them; or, if they are willing, you can cause them to teleport to an unoccupied space of your choice adjacent to you.

Gragnok Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon.

Command of Enmity. The blade has 2 charges. While you are wielding the blade, you can expend a charge from the blade to use your vow of enmity feature without expending a use of channel divinity. In addition, when you use your vow of enmity feature, allies that you choose within 60 feet of you gain advantage on attack rolls against the target creature until the start of your next turn, in addition to the normal effects of vow of enmity. Your vow of enmity feature also gains this benefit even when you expend channel divinity to use it.

The blade regains all expended charges at the end of each long rest.

Team Skill
After Gragnok awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

School of Hard Noks. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When your attuned ally is hit by an attack roll, you can use your reaction to move up to 15 feet towards your attuned ally. If you end this movement adjacent to your attuned ally, they gain a 1d4 bonus to their armor class against the triggering attack, which lasts until the start of their next turn.

Jack Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon. While you are wielding the weapon with only one hand, it is considered a finesse weapon for you.

Sorcerous Intervention. The blade has 4 charges. While you are wielding the blade, when you see a creature within 60 feet of you cast a spell, you can use your reaction to expend charges from the blade as if they were sorcery points, and apply one of your metamagic options to their spell, if they are willing. In addition, the creature is enshrouded with elemental energy until the end of their next turn, gaining resistance to a damage type that you choose from the following options: acid, cold, fire, lightning, or thunder.

The blade regains all expended charges at the end of each long rest. If the blade does not have any remaining charges, you can spend your own sorcery points instead to activate the blade's properties.

Team Skill
After Jack awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Jack Be Nimble. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When your attuned ally deals damage to a creature within 60 feet of you, you can use your reaction to move up to 15 feet toward that creature without provoking opportunity attacks.

Rye Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon. In addition, you are considered proficient with this weapon, regardless of your normal weapon proficiencies.

Inspi-rage-tion. While you are wielding the blade, when you use your bardic inspiration feature, the creature that you choose gains the benefits of your rage feature until the start of your next turn, in addition to gaining a bardic inspiration die. In addition, at the start of the creature's next turn, they roll on your infernal surge table, using your DC for the effects of the surge if necessary.

Team Skill
After Rye awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Nothing To Louche. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When the attuned ally expends one of your bardic inspiration dice, you gain temporary hit points equal to the number that they roll.

Malkoth Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon.

Infernal Avenger. While attuned to the blade, the number of spells that you can prepare each day increases by 2.

The blade has 3 charges. When you see a creature within 60 feet of you take damage from another creature that you can see within 60 feet of you, you can expend a charge from the blade to cast hellish rebuke as a 3rd-level spell against the attacker as if you had taken the damage.

The blade regains all expended charges at the end of each long rest. If the blade does not have any remaining charges, you can use your infernal legacy racial trait instead to activate the blade's properties. When you use your infernal legacy racial trait in this way, you still cast hellish rebuke as a 3rd-level spell.

Team Skill
After Malkoth awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Malkoth Cocktail. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When your attuned ally deals damage to a creature with a spell, the next time you deal damage to the same creature with a spell, you can roll the damage dice twice and use either total.

Odell Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon.

Runic Bond. The blade has 2 charges. While you are wielding the blade, you can expend a charge from the blade to use your giant’s might feature without expending the feature. In addition, when you use your giant’s might feature, allies that you choose within 60 feet of you gain the benefits of your giant’s might feature until the start of your next turn, in addition to the normal effects of giant’s might. Your giant’s might feature also gains this benefit even when you expend the feature normally instead of using the blade's charges.

The blade regains all expended charges at the end of each long rest.

Team Skill
After Frog awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Odell Tango. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When your attuned ally deals damage to a creature within 5 feet of you, you can use your reaction to move up to 15 feet without provoking opportunity attacks.

Patches
You have a +2 bonus to attack and damage rolls made with this magic weapon. In addition, you are considered proficient with this weapon, regardless of your normal weapon proficiencies.

Whims of Chaos. While attuned to the blade, the number of spells that you can prepare each day increases by 2. In addition, you can expend one use of your channel divinity feature as an action to grant yourself and two allies that you can see within 60 feet of you each a random magical boon, which lasts for 1 hour. For each boon, roll 1d4 times on the whims of chaos table, and choose which boon to grant from the ones that you roll.

Team Skill
After Patches awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Don't Break The Ice. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When you cast a spell that restores hit points to your attuned ally, you gain temporary hit points equal to half of the hit points that you restored.

XVIII Properties
You have a +2 bonus to attack and damage rolls made with this magic weapon. While you are wielding the weapon with only one hand, it is considered a finesse weapon for you.

Divert Empowerment. When you use your vampiric bite racial feature to empower yourself, the blade also becomes empowered for 1 minute, during which time your symbol on the blade glows crimson. As a bonus action while the blade is empowered, you can grant a creature that you can see within 60 feet of you (other than yourself) one of the empowering effects of your vampiric bite.

Team Skill
After XVIII awakened Syntithenai, he permanently gained the following skill, which he retains even after he ends his attunement to the blade.

Edge of XVIII. At the end of each long rest, you can choose an ally to be attuned to your Team Skill. The ally remains attuned to your Team Skill until you complete another long rest. You can only use your Team Skill on the attuned ally, and you can only ever have one ally attuned to your Team Skill at a time.

When your attuned ally deals damage to a creature within 10 feet of you, you experience a surge of vitality. Your speed increases by 10 feet, and you gain advantage on Strength and Dexterity checks and saving throws until the end of your next turn.