Frostguard

Keepers of ancient secrets and servants of something older than ice. Your blood may carry the touch of the Iceborn, or something darker.

Ability Score Increase. Intelligence +1

Whispers of the Watchers. You gain proficiency in Arcana or Religion (your choice). Once per long rest, when dealing with magic related to cold, time, or ancient ruins, you may roll the check with advantage.

Rimebound Magic. You know the Frostbite cantrip. At 3rd level, you may cast Armor of Agathys once per long rest. At 5th level, you may cast Hold Person once per long rest. Intelligence is your spellcasting ability for these spells.

Iceblooded Control. When a creature within 30 feet of you rolls saving throw against becoming paralyzed, restrained, or incapacitated, you may use your reaction to give that creature disadvantage on that roll. You may use this ability a number of times equal to your Intelligence modifier (minimum once) per long rest.