Power of the Frost Giant Everlasting One

You’ve manifested some of the power of a Frost Giant Everlasting One, granting you the following benefits:

Ability Score Improvement. Increase your Strength or Constitution by 1, to a maximum of 20.

Resilience of a Frost Giant. You gain immunity to cold damage.

Regeneration. At the start of each of your turns, you regain a number of hit points equal to half your level. If you take acid or fire damage, this feature doesn’t function at the start of your next turn.
    You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a short or long rest. Alternatively, you can use your action to regain 1d4 expended uses.

Vaprak's Rage. At the start of your turn, you can use a bonus action to enter a rage. The rage lasts for 1 minute or until you are incapacitated. While raging, you gain the following benefits if you aren’t wearing heavy armor:

• If you are smaller than Large, you become Large. If you are already Large you become Huge. Any equipment you are wearing or carrying changes size with you.
• You have advantage on Strength checks and Strength saving throws.
• When you make a melee weapon attack using Strength, you gain a +4 bonus to the damage roll. If you have at least one level in barbarian this stacks with the Rage Damage bonus you have from that class.
• You have resistance to bludgeoning, piercing, and slashing damage.
• You can attack twice, instead of once, when you take the Attack action on your turn. You ignore this benefit if you already have a feature, like Extra Attack, that gives you extra attacks.

If you are able to cast spells, you can’t cast them or concentrate on them while raging. Once you use this feature, you can't use it again until you finish a short or long rest.