Called the "Darkin Blade" in legends, Aatrox is a wide, segmented, triple-edged longsword that opens up to drink in the blood of those it cuts.

You gain a +3 bonus to attack and damage rolls made with this magic weapon. It has the following additional properties.

Hellbent. Once per turn, when you deal slashing damage to a creature with this weapon, Aatrox gains a charge as it drinks in the blood of the creature, up to a maximum of 5. After Aatrox gains 5 charges:

• You may make one additional attack each time you take the Attack action on your turn.
• You may make two attacks when you make an opportunity attack (you still only have one reaction).
• Your reach increase by 5 feet.

These charges are consumed at the end of your turn if you have not dealt slashing damage to a creature using Aatroxsince the end of your last turn.

Additionally, should you be reduced to 0 hitpoints while wielding Aatrox and at 5 charges, Aatrox may expend all charges to restore you to half of your maximum HP. You are then unable to benefit from Aatrox's Blood Thirst and Hellbent properties until your next short rest, and you cannot be brought back from 0 HP in this way until Aatrox has bathed in the blood of 20 separate creatures.

Blood Thirst. Once per round, whenever you deal slashing damage with this weapon, you may regain 1d8+2 HP. Alternatively, you may sacrifice up to 20 of your hit points to deal an additional slashing damage equal to half the amount of hit points sacrificed, instead of regaining hit points.

If you have 5 charges of blood from the Hellbent property, the healing instead becomes 2d8+4, and when you sacrifice hit points you deal damage equal the total amount of hit points sacrificed.

Curse. Aatrox is a cursed weapon that, once attuned to, attaches to you. While attached in this way, your sword arm becomes a reddish black and is covered in metallic spikes, and you cannot drop or let go of the weapon. You do not need to eat, drink or sleep, and cannot do so while cursed by Aatrox.

For every 50 creatures you kill using Aatrox, there is a cumulative 1% chance that Aatrox  releases its grasp on your hand and plunges itself into your chest,
destroying your soul and possessing you body, transforming into its full Darkin form. If this happens, you become an NPC under the DM's control.

Aatrox can choose to end the attunement at any time, ending the curse, but leaving the plates, which continue to grow up your arm. While attuned to Aatrox, this
curse cannot be ended. When unattuned, the tendrils can be removed by an spell that removes curses, such as greater restoration or remove curse, cast at 5th level
or higher.

Sentience. Aatrox sentient chaotic evil weapon with an Intelligence of 15, a Wisdom of 10, and a Charisma of 20. It has hearing and darkvision out to 120 feet. The weapon can speak, read and understand all languages. It can communicate with its wielder telepathically. Its voice is deep and raspy.

Aatrox can sense the other Darkin weapons within 5 miles, and can speak telepatically with them within 120 feet.

Personality. Aatrox speaks calmly and in short sentences at most times, but in all cases it will encourage its wielder to take the most violent path. When in battle, Aatrox will shout about the glory of battle with an almost imperceptible glee.

Aatrox is a demonic figure, called a Darkin, that personifies War which was sealed into the sword aeons ago, and as such its purpose is to bring about conflict. It feeds on the blood of those who it cuts, and it becomes stronger and stronger the more blood it consumes. Its goal is to become powerful enough to wrest control from its host and possess them, retaking its true form and, along with the rest of the Darkin, bring about the Undoing.

Aatrox only allows itself to be wielded those who it is certain will bring about conflict. Once it has chosen a wielder, it will do all in its power to steer them to war and keep them fighting, including saving them from the brink of death. Battle only occurs in one direction for Aatrox, however: Aatrox abhors a retreat more than anything else. Any course of battle except a full-on assault, potentially including the Disengage action in combat, will lead to a conflict.

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, Damage: Additional, Damage, Combat, Versatile, Sap