Haemstrike

Weapon (mace, warhammer, or maul), uncommon (optional attunement)
  This weapon is naturally more attracted to foes bearing ferrous metals, allowing it to strike them with more force. Those who align themselves more closely with the weapon are granted the ability to manipulate gravity, telekinetically pulling creatures and objects into range of its jagged face swings.
  You have a +1 bonus to attack and damage rolls made with this magic weapon. This bonus is increased to + 2 if your target is made of ferrous metal or is wearing ferrous armour.
  Optional Attunement. If you choose to attune to this weapon, it gains the Attraction property. When you activate a property granted by this optional attunement, roll a d4. On a 1, haemstrike’s optional attunement properties can’t be activated until the next dawn.
  Optional Attunement: Attraction. As an action, you can can point haemstrike at a target you can see within 30 feet of you. If the target is an object whose weight is less than or equal to 30 times your Strength score, the object is pulled up to 15 f eet towards you. If the target is a creature, make a Strength (Athletics) check contested by the creature’s Strength (Athletics). If the target is made of ferrous metal or is wearing ferrous armour, the creature has disadvantage on this check. On a success, the creature is pulled up to 15 feet towards you. On a failure, the creature remains where it is, but, if you are neither grappled nor restrained, you can choose to let yourself be pulled up to 15 feet towards it.
  Rare variant: Increase the attack and damage bonus to + 2 (or + 3 if the target is made of ferrous metal or is wearing ferrous armour). Increase the distance a target can be pulled by the Attraction property to 20 feet. Increase Optional Attunement’s d4 to a d6. The weapon gains the Magnetic Shockwave optional attunement property.
  Optional Attunement: Magnetic Shockwave. When you hit a target with haemstrike, you can use a bonus action to cause an eruption of supercooled magnetite shards. Each creature other than you within 5 f eet of the target must succeed on a DC 15 Dexterity saving throw or take 2d6 cold damage and 2d6 piercing damage. Creatures made of ferrous metal or wearing ferrous armour have disadvantage on this saving throw.
  Very rare variant: Increase the attack and damage bonus to + 3 (or + 4 if the target is made of ferrous metal or is wearing ferrous armour). Increase the distance a target can be pulled by the Attraction property to 30 feet. Increase Optional Attunement’s d4 to a d8, and the DC of Magnetic Shockwave to 16. The weapon gains the Magnetic Shockwave and Dragon’s Roar optional attunement properties.
  Optional Attunement: Dragon’s Roar. When you make a weapon attack with haemstrike, you can use a bonus action to cause the hammer to roar before you make the attack roll. Each creature other than you within 15 f eet of you must succeed on a DC 16 Wisdom saving throw or become frightened of you until the end of your next turn. If the target of your attack fails this saving throw, your attack has advantage.