Duskfield

 You call on the elemental power of Frost. Duskfield generates a sphere of Cold energy that Slows and eventually Freezes foes caught within. For the duration, a domed magical aura of Cold spreads from a point you can see within range and fills a 5 foot-radius Sphere. The area is covered in a shimmering, obscuring, dark blue light. The area is Dim Light.  

 Enemy creatures entering the field or within it when it is formed have the Slowed condition: The creatures movement speed is reduced by 10ft and it moves at half speed as though in Difficult Terrain. On its turn, a slowed creature can take either an Action or a Bonus Action, not both, and it may only attack once if it takes the Attack Action. Attack rolls against a Slowed creature have Advantage. Slowed creatures have Disadvantage on DEX Saving Throws. 

 If an enemy ends its turn within the field it must make a CON Saving Throw equal to your Spell Save DC. On a Failure the enemy is encased in ice and Frozen for 1 round. Frozen enemies are Paralyzed and Vulnerable to Fire and Bludgeoning damage. On a success, no additional effect besides Slowed.