Pact of Cania

You have made a pact with the Lord of Cania, Mephistopheles. Also kown as the Cold Lord and the Lord of Hellfire, Mephistopheles has a cool, calculating surface, which is contrasted by the hot-headed and flamboyant part that lies beneath. This contrast is mirrored in the spells one ganis from making a pact with him. First, you gain Spells which are related to Ice and all types of cold, but as you delve deeper and deeper into magic and get more useful for your patron, he will begin granting you fire-based spells.

Paradox of Mephistopheles.

Just like your master, your magic is a paradox in and of itself. Before you reach Level 10, you can not learn fire-related spells through any means other than the Wish Spell, owing to the cold and calculating appearance of your patron. Starting at Level 10, however, you are uncapable of learning any new ice-related spells through any means other than the Wish Spell, owing to the true, hot-headed and grandiose nature of the Lord of Hellfire.

Cania's Blessing

Starting at Level 1, when you hit a creature with a melee attack, you can add 1d4 cold damage to the damage dealt. If you use this feature, you must complete a short rest before you can use it again. Starting at Level 7, you instead add 1d6 cold damage to your attacks, which increases to 2d6 at level 12.

Cold Lord's Associate

Starting at 6th level, your affiliation with the Cold Lord of Cania manifests itself in an aura around you with a range of 5 feet. If a creature ends its turn within range, it must make a Constitution Saving Throw with a DC of 12 + your charisma modifier. On a failed save, it takes 2d6 cold damage or half as much on a successful one. Starting at 10th level, the Constitution Saving Throw has a DC of 14 + your charisma modifier and instead of 2d6 cold damage, the affected creatures instead take 3d6 fire damage on a failed save or half as much on a successful one. 

Hellfire Initiate

Your loyalty to the Lord of Cania has paid off and he now regards you as worthy of the secrets of Hellfire. Starting at 10th level, you gain Resistance to Fire Damage. Damage from silver and magic weapons is not affected by this ability. If you haven't already, you learn the Fireball spell. If you already know this spell, choose a different fire-related spell that you can learn at this level.

Wielder of Hellfire

Your mastery of Hellfire, that has been granted to you by the Archduke of Cania allows you to burn your enemies with Hellfire whenever you attack them. Starting at 14th level, when you make an attack against a creature, you can choose to add 4d6 fire damage to the attack and set the target on fire for 18 seconds (3 rounds). You can use this feature three times per long rest.