Leviathan

"You will always be a monster." "I know. But I am your monster no longer." -Unknown
A weapon stained with the blood of mortals and gods alike. Sundered an age ago. Reforged by your hand.
A beautiful kintsugi-style adamantine and gold blade etched with the runes of the Oracles, set atop a long handle of ivory dragonbone. At the hilt, inlaid in gold, lies a small marking of a longsword impaling a rose.

Awakened

All damage dealt by this weapon is considered magical in terms of overcoming resistances.
Deals 2d12 slashing damage, and grants +2 to attack and damage rolls.
While attuned, the wielder becomes resistant to Cold damage.
Leviathan has 7 charges. On a successful hit, expend one charge to inflict extra Cold damage equal to your character level. The axe regains all expended charges daily at dawn. If you expend the last charge, roll and regain 1d4 charges. Once you regain charges in this way, you may not do so again until you complete a long rest.
When thrown, you can, as a reaction, will the axe to return to your hand. All enemies in the path of the axe as it returns must make a DC12 Dexterity saving throw or take 1d6 bludgeoning damage. If you begin your turn by recalling the axe, your next attack has advantage when made on the same turn.
Proficiency with a greataxe allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Exalted

All damage dealt by this weapon is considered magical in terms of overcoming resistances.
Deals 3d12 slashing damage, and grants +3 to attack and damage rolls.
While attuned, the wielder becomes resistant to Cold damage.
Gains the thrown property, with a short range of 30ft and a long range of 60ft. When thrown, attacks are made at advantage. On a successful hit, the target must make a DC16 Strength saving throw or be frozen solid (Paralyzed) as long as the axe is embedded within them, up to 30 seconds. Target may attempt to break out of freeze at the start of their turn. If the axe is recalled while embedded in a frozen target or the time expires, the ice shatters, dealing an additional 2d8 cold damage.
Leviathan has 10 charges. On a successful hit, expend one charge to inflict extra Cold damage equal to your character level. The axe regains all expended charges daily at dawn. If you expend the last charge, roll and regain 1d6+2 charges. Once you regain charges in this way, you may not do so again until you complete a long rest.
As a reaction, you can will the axe to return to your hand. All enemies in the path of the axe as it returns must make a DC12 Dexterity saving throw or take 1d12 bludgeoning damage. If you begin your turn by recalling the axe, your next attack has advantage when made on the same turn.
As an action, you can cast the spell Investiture of Ice once per long rest.
Proficiency with a greataxe allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Item type

Weapon, Melee