Frost Watch

Posted in the far edges of the world, guarding beings entombed in eternal ice. Patrolling the walls of the mage capitol, ever ready for an assault. The order of the frost watch defends those around them through the accumulation of icy barriers and walls.

Armoring Frost
Starting when you make this covenant at 3rd level, the arcane rune that conjure the armor of agathys are carved into your armor. Whenever you are hit with a melee attack while you still have temporary hp, the attacker takes cold damage equal to the "protection" property of your armor.

Walls of Ice
Also at 3rd level, You have become adept at controlling the ice on your armor to shape the battlefield around you. As a bonus action on your turn, you may expend any number of your temporary hit points to create the terrain effects listed below, costing 5 temp hp each:
- Slippery Sheet: Choose a 5ft square within your timely aid aura, it becomes Icy terrain.
- Icicle: Create a pillar of ice within your timely aid aura, it occupies a 5ft square and can provide half cover
- Barricade: Choose a Door, window, or other open entrance to an area that occupies no more than a 5ft square. Creatures cannot pass through that opening unless they succeed on a DC 15 str check to break the barricade.
All terrain features last for 10 minutes, or until you end initiative.

Accumulating Plates
Starting at 6th level, your armor retains protection with its strange icy magic. When you gain temporary hp, it can stack with any existing temporary hp, however, your total temp hp gained this way cannot exceed half your max hitpoints.

Vigilant Blizzard
Starting at 11th level, you begin to conjure an arcane storm around yourself. At the beginning of your turns when you have temp hp, you may choose to plunge your timely aid aura into a blizzard. You may dismiss this effect as a free action and it lasts until you do so. Allies of your choice in the aura are considered heavily obscured, and whenever you start your turn with the blizzard active, you gain pb temp hp.

Domain of Rime
At 17th level, When you use the Help action on an ally while vigilant Blizzard is not active, they gain temp hp equal to half your vanguard level.
Additionally, When you have Vigilant blizzard active, squares within the aura are considered icy terrain for creatures you did not choose to obscure with the aura. You may Use your walls of Ice feature on squares out side of your timely aura, up to 120 feet away from you.