From Ages Long Since Forgotten
This weapon, once wielded by Annam, The All-Father himself was used against those who would defy the ordning and refuse his beliefs and ideals. Created long ago by a primordially infused Cloud Giant Sorcerer named Xetarum, who was once Annam's most trusted adviser - until Xetarum was ordered to take the weapon upon himself, and venture the lands and ensure the survival of all subjects under his rule. After so long, it had been lost to time and stolen countless times. Many incapable of even understanding the nature or history of the item.

This magical heavy crossbow changes size according to the its wielder, though it is always at least 6ft long in length, with a cross-plate span of 5ft.
Even lifting this magical heavy crossbow requires the wielder to have a strength of 14 or higher, or a dexterity of 18 or higher. 

You gain a +2 bonus to attack and damage rolls made with this heavy crossbow.
This heavy crossbow has 12 charges, and regains 1d6+2 charges at dawn. 
The heavy crossbow itself is covered in what look like sturdy shale plates, with magma seeping through the cracks between them - anyone who tries to wield this weapon and is not attuned to it takes 3d10 fire damage and 3d10 cold damage. 

An enemy hit by an attack made with this heavy crossbow has their movement speed decreased by 10ft until the start of the wielder's next turn. After a creature suffers this penalty, they are immune to this effect activating again during the same round.
Any enemy hit by an attack made with this heavy crossbow takes an extra 1d4 of fire damage for each charge currently remaining in the heavy crossbow.

Spellcasting
Hill Giant's Sloth
You may expend two charges, and from this heavy crossbow, cast "Slow" at 3rd level, without expending a spell slot or requiring material components. Once you do this, you cannot expend charges in the same way until the next dawn. You may cast the spell in this way even if you have no free hands, and can instead do so by firing a bolt into the air above you. 

Stone Giant's Envy
You may expend three charges, and from this heavy crossbow, cast "Stoneskin" at 4th level, without expending a spell slot or requiring material components. Once you do this, you cannot expend charges in the same way until the next dawn. You may cast the spell in this way even if you have no free hands, and can instead do so by firing a bolt into the air above you.

Frost Giant's Wrath
You may expend four charges, and from this heavy crossbow, cast "Cone Of Cold" at 5th level, without expending a spell slot or requiring material components. Once you do this, you cannot expend charges in the same way until the next dawn. You may cast the spell in this way even if you have no free hands, and can instead do so by firing a bolt into the air above you.

Fire Giant's Greed
You may expend five charges, and from this heavy crossbow, cast "Soul Cage" at 6th level, without expending a spell slot or requiring material components (the cage in which the soul resides is created by the magic of the crossbow, and hangs from the stock of the weapon). Once you do this, you cannot expend charges in the same way until the next dawn. You may cast the spell in this way even if you have no free hands, and can instead do so by firing a bolt into the air above you.

Cloud Giant's Pride
You may expend six charges, and from this heavy crossbow, cast "Whirlwind" at 7th level, without expending a spell slot or requiring material components. Once you do this, you cannot expend charges in the same way until the next dawn. You may cast the spell in this way even if you have no free hands, and can instead do so by firing a bolt into the air above you.

Storm Giant's Truth
You may expend seven charges, and from this heavy crossbow, cast "Sunburst" at 8th level, without expending a spell slot or requiring material components. Once you do this, you cannot expend charges in the same way until the next dawn. You may cast the spell in this way even if you have no free hands, and can instead do so by firing a bolt into the air above you.

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

Notes: bard, cleric, druid, sorcerer, warlock or wizard, Damage, Debuff, Combat, Ammunition, Heavy, Loading, Range, Two-Handed, Push