Ray of Frost Specialist

Out of the many cantrips that you can learn or already know, Ray of Frost is your forte.

• Add the ability score modifier you use for spellcasting to the damage rolls. If you already can do this, for example by the Element Affinity feat that Draconic Ancestry sorcerors have, you instead add half of your proficiency bonus to damage rolls (minimum of 1, rounded up).
• You can cast this cantrip during an Attack of Opportunity on an enemy.
• You have an alternative mode where you have the option to shoot the ground forming a 5ft by 5ft square sheet of ice that lasts for a minute. When a someone walks on the sheet of ice, they have to make a Dex save against you spell DC or else they spill and become prone and have their movement speed reduced as well as take damage from the Ray of Frost if you chose to. You can use this feature a number of times equal to the ability score modifier you use for spellcasting (minimum of 1). You can have only one sheet of ice in play at a time, but the number of increases by one at 5th level, again at 11th level, and again at 17th level. The ice sheets can be dispelled as a bonus action. Regain this feature on long rest. 
• At 5th level, you reduce the speed of the target by 15ft. At 11th level, you reduce the target speed by 20ft. At 17th level, you reduce the target speed by 25ft.
• On a critical hit, you reduce the speed of the target by another 5ft.