Soul of the Blue Veil

"In the land of the living, are Sorcerers made,
But not all their kind wield 'material' aid.
For not from the sleepless, come these casters' might,
but the birthright of dreams, and fancies of flight.
A realm beyond waking, beyond East and West,
a realm rarely accessed, beyond nightly rest.
It is there, past the Blue Veil. Can you reach it, my friend?
Or will it all slip away, when you wake up again?"

(Note: This class cannot normally be accessed by races that don't normally sleep, such as Elves or Warforged.)

Knowledge of the Blue Veil:

If a spellcaster succeeds in casting a spell on you, or hits you with a spell attack, you can learn that spell, regardless of the spell's class of origin. To do so, the spell's level has to be equal to or less than half your Sorcerer level (rounded up). If it isn't, you can roll a 1d20. If the result is equal to or higher than 10 + the spell's level, you can learn it, although you will still need the proper spell slots in order to cast said spell. These spells and cantrips count as Sorcerer spells for you, and Charisma is your spellcasting ability for these spells.

The Unpierced Veil:

Should you attempt to learn a spell or cantrip that would cause the number of spells or cantrips known to exceed the allotted number of Spells Known or Cantrips Known on the Sorcerer table, you must either replace a corresponding spell/cantrip currently known, or your attempt to learn the new spell/cantrip will automatically fail.

Cloaked by the Blue Veil:

You can invoke this class feature as a reaction to a spell or spell attack, so long as it's one that you don't currently know. You gain resistance to the damage of the triggering effect, until the start of your next turn. You can use this feature a number of times equal to your Proficiency Bonus, and all expended uses are restored when you finish a long rest.

Pierce Beyond the Blue Veil:

You are no longer restricted by The Unpierced Veil, and thus no longer have to replace currently-known spells in order to learn new ones. In addition, you automatically add Dream of the Blue Veil to your list of spells known, if you don't know it already, and can cast it once per long rest, without expending a spell slot.

Dream of the Azure Sanctuary:

If you die from unnatural causes, roll 1d4, then add 6. If you are left unrevived after that many hours have passed, then you wake up in a safe location previously visited within 24 hours of your death. While you retain full memory of how you died, the memory of your death itself feels like no more than a bad dream or a nightmare. You gain no benefits of a short or long rest, and cannot use this feature again for a number of days equal to the die result (1-4). You also cannot learn any spell that landed the killing blow on you, unless you were conscious when that spell was cast.