You have a +1 bonus to attack and damage rolls made with this magic weapon.

The Ruby Sword of the Unseelie Court", encrusted on the hilt and pommel with rubies and elvish platinum filigree.

The sword is Intelligent, currently inhabited by the soul of the Ruby King himself, Lazarius, from which the mental abilities and alignment of the sword inherit. 

Weapon Abilities (inherited): Intelligence 14 (+2), Wisdom 16 (+3), Charisma 16 (+3)

Weapon Alignment: Neutral Evil (inherited)

Purpose: The Ruby Sword of the Unsealy Court's motivations vary from normal intelligent magical items, since the intelligence is taken from those who die with it in their grasp. Lazarius is presently tired of immortality and wishes to achieve final death. Because of this, he will help whenever possible at first, but later on it will begin attempting to manipulate the wielder to take actions that might get them killed (getting his wielder killed will allow him to move on to the afterlife, trapping the player's soul in the sword). If resisted the sword might attempt to take over the wielder if the odds are increasingly in favor of the wielder dying. Lazarius is cautious, however, and will avoid revealing his presence or intentions for as long as possible.

The kings sword is a cursed phylactery. If anyone wields the sword and is reduced to zero health with it in their hand/s, their soul is drawn into the blade and the weapon becomes intelligent with their alignment replacing those of the sword (Willpower saving throw DC 10 upon being reduced to zero, with failure automatic if the character fails their death saves). The sword is imbued with the soul of the Ruby King, Lazarius the Wise presently. A soul may be removed from the sword via a wish spell, or by the existing soul trapped in the weapon being pushed out by a new occupant (usually much to the relief of the previous occupant). The current occupant of the sword may choose not to leave as well, thus a good relationship with the weapon is paramount to avoid having one's soul trapped upon their demise. 

Note: When devoid of a resident soul, the Ruby Sword of the Unseelie Court is only of rudimentary intelligence (Intelligence 10, Wisdom 10), and can only communicate via emotion. Additionally, the sword imparts feelings of invincibility in the wielder, granting them immunity to fear. When faced with a dangerous situation, the wielder must make a Wisdom saving throw DC 12, or be compelled to take unnecessary risks.

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Immunity: Frightened, Damage, Combat, Versatile, Sap