You have a +2 bonus to attack and damage rolls made with this magic weapon. In addition, when you're damaged by a creature in reach, you may use your reaction to make one melee attack against it with this weapon.
You're unwilling to part with this weapon while attuned to it. While attuned, you have disadvantage on attack rolls with weapons other than this one.
Whenever a hostile creature damages you, you must succeed on a DC 15 Wisdom saving throw or go berserk. While berserk, you must use your action on each of your turns to attack the creature nearest to you with the weapon. If you can make extra attacks as part of the Attack action, you use those extra attacks, moving to attack the next nearest creature after you fell your current target. If you have multiple possible targets, you attack one at random.
You're berserk until you start your turn with no creatures within 60 feet of you that you can see or hear. Alternatively, an ally can use an action to make a DC 15 Charisma (Persuasion) check and if successful, you're no longer berserk. Only the Remove Curse spell allows you to end attunement to this item.
This item corrupts. See the "Infernal Item Corruption" section.
You have Disadvantage on attack rolls with a Heavy weapon if it's a Melee weapon and your Strength score isn't at least 13 or if it's a Ranged weapon and your Dexterity score isn't at least 13.
A Reach weapon adds 5 feet to your reach when you attack with it, as well as when determining your reach for Opportunity Attack with it.
A Two-Handed weapon requires two hands when you attack with it.
If you hit a creature with a melee attack roll using this weapon, you can make a melee attack roll with the weapon against a second creature within 5 feet of the first that is also within your reach. On a hit, the second creature takes the weapon's damage, but don't add your ability modifier to that damage unless that modifier is negative. You can make this extra attack only once per turn.