Draconic bloodline sorcerer. Take a cold option. Get the Morning Frost staff in the Underdark and the Winters Clutches gloves from the lady in mountain pass who wants gith egg. After killing gith boss, there’s a necklace of elemental something or other in the room to the right. In Last Light there’s a room in the back on the bottom floor with a floorboard that has a snowburst ring hidden in it. Also get the super awesome Potent robes from the Bard tiefling by going to Moonrise and saving everyone. While you’re there, stop in the necromancers room for the coldbrim hat. Also have someone nearby with create water. Make sure to take haste.
Congrats. You’re now pumping out a minimum of an extra 10-15 damage per hit from ray of frost without them being wet and a huge attack roll bonus. The ray will also stack something called encrusted with frost which can outright freeze them solid and make them skip their turn and chilled as well which gives them cold vulnerability. Patches of frost will also immediately appear under them, forcing them to make a save or fall probe. Everytime you hit them they also have to make saves. Burn every spell slot for metamagic and twin/quicken to your hearts content. Hasten yourself and you’re harder to hit and blast more.
So much fun. I can write a better guide if people want. I’m on toilet and half asleep at moment.