You have resistance to Cold damage. You learn the Cone of Cold spell. You can cast this spell using spell slots if you have ones of the appropriate levels. This spell uses your spellcasting modifiers, or has a DC of 17. Additionally, you gain the following effects

• This boon has 10 charges that recharge on a long rest
• You may expend 1 charge to ignore resistance or immunity to cold damage dealt by you or creatures created by your spells or features until the start of your next turn.
• When you deal cold damage you may expend 2 charges to force the affected creatures to make a constitution saving throw.  The save DC is 17 or your spell save dc.  On a failed save, the creature’s movement speed is set to 0 until the start of your next turn.  On a successful save, the creature’s movement speed is halved.
• You may expend 1 charge to cast Cone of Cold using one of your spell slots as a bonus action. Alternatively, you may spend 3 charges to cast the spell as a bonus action without consuming a spell slot and ignoring the material component.