Frost of Stygia

You learn to call on cold of the river styx to serve your
commands. You gain the following benefits:
• Increase your Intelligence or Charisma score
by 1, to a maximum of 20.
• When you roll cold damage for a spell you cast,
you can reroll any roll of a 1 on the cold damage
dice, but you must use the new roll, even if it is
another 1.
• Whenever you cast a spell that deals cold
damage, you can cause Ice crystals to wreathe you
until the end of your next turn. The cold
doesn’t harm you or your possessions, and the crystals
shed bright light out to 30 feet and dim light
for an additional 30 feet. While the crystals are
present, any creature within 5 feet of you that
hits you with a melee attack takes 1d4 cold
damage.