Dream Cartography

The sleeping mind stares out into an endless vista, stitching together the thoughts and actions of the day into dreams. Yet, in a world of magic, especially to a practitioner of the arcane arts, dreams hold far greater revelations. By mapping one’s own mental landscape, new insights into reality can be found and harnessed. Many of these wizards often draw the attentions of the Keeper of the Depths, who may greet them by offering bargains both simple and terrible. Few have the liberty of continuing their pursuits without attracting its attention, as the ripples of magic across the dreamscape are particularly attractive to this ancient nightmare. You’ve chosen to begin to map your own dreams by pursuing this tradition, seeking insight into the lands beyond the veil of sleep.

This is not an original creation of mine. This comes from Genuine Fantasy Press's "The Compendium of Forgotten Secrets" free abridged sourcebook. If you enjoy this subclass, I highly recommend going to their website and checking out their other content, as it's all high quality.

Dreamscape Spellbook

When you choose this tradition at 2nd level, you develop a peculiar memorization technique. You gain darkvision out to 60 feet. Whenever you are in darkness, you can access your dreamscape spellbook, which is a mental construct that you’ve created to aid in your understanding of the spells you learn. When you are inscribing a spell into your physical spellbook during a long rest, you can choose to also inscribe the spell into your dreamscape spellbook without cost. You can copy down spells from your dreamscape spellbook into a physical spellbook in half the time it would normally take you to copy a spell.

Upon the Veil of Night

Also at 2nd level, you learn to use your spellcasting to call forth fragments of your dreamworld into reality. Whenever you cast a spell of 1st level or higher using a spell slot, you can use your bonus action to create an effect based on the school of the spell you cast. You can use this feature a number of times equal to your Intelligence modifier (minimum 1), and you regain all expended uses when you finish a long rest.

• Abjuration: You dream of a wall, infinite in majesty. Choose an unoccupied space that is up to 10 feet high, 10 feet wide, and one foot thick. A dreamscape wall appears in the location that lasts until the end of your next turn. The wall has hit points equal to your Intelligence modifier.
• Conjuration:  You dream of a portal to faraway lands. Choose an unoccupied space within 5 feet of you. A portal appears in this space that lasts until the start of your next turn. Whenever you or another creature enters the portal, they teleport to an unoccupied point of your choosing within 20 feet of the portal, determined by you when they enter.
• Divination: You dream of a star, shining above the world. A radiant light appears at a location of your choosing within 30 feet of you. This light counts as natural sunlight and casts bright light in a 50-foot radius and dim light in an additional 50-foot radius. The light lasts for 1 minute or until you dismiss it as a bonus action.
• Enchantment: You dream of a beautiful landscape. One creature of your choosing within 30 feet of you must make a Wisdom saving throw against your wizard spell save DC. If they fail, they are charmed during their next turn and will move directly towards you by the safest open route.
• Evocation: You dream of a great cataclysm. Choose one creature targeted by your spell or a creature within 30 feet of you. That creature must make a Strength saving throw against your wizard spell save DC or be knocked prone.
• Illusion: You dream of a maze of mirrors and mist. You create a 20-foot-radius sphere of fog centered on yourself. The sphere spreads around corners, and its area is heavily obscured, but you can see clearly from inside the fog.
• Necromancy: You dream of an open grave. Choose a creature within 30 feet of you. The target must make a Wisdom saving throw against your wizard spell save DC. If they fail, the next time they take damage from a weapon attack, they also take extra necrotic damage equal to your wizard level.
• Transmutation: You dream of a world, strange yet familiar. Choose a number of 5-foot cubes within 30 feet of you equal to the level of the spell cast. These cubes become difficult terrain for 1 minute.

Decent into the Depths

Starting at 6th level, you learn to drag others with you into your dreams. Whenever you cast a spell of 1st level or higher while you have access to your dreamscape spellbook, you can use your bonus action to enter a harmless dreamscape until the end of your next turn, reappearing at a location of your choosing within 30 feet of the point of your departure. You can touch a creature when you enter, bringing them with you. Neither of you can use actions or take damage while in this dreamscape. If you cannot reappear at the point you chose, you are shunted to the nearest open location and take 10 force damage.

In the Place Beyond

At 10th level, your dreams come to you even in your waking moments. You can now access your dreamscape spellbook while you are in either dim light or darkness.

Additionally, you can choose to cast spells as though you were located at any point that you can see within 15 feet of your current location, provided that location is within dim light or darkness.

The End of Sleep

At 14th level, you have touched the primordial dreams of the universe. The knowledge to control your dreams resides within them, but only if you can satiate the cost to comprehend it's infinite knowledge. When you cast a spell of 6th level or higher using a spell slot, you can choose to recover all expended uses of your Upon the Veil of Night feature. When you do this, target one humanoid creature within 20 feet of you that you can see. If there are no other targets available, you must target yourself. The target must make a Wisdom saving throw against your wizard spell save DC. If a failed save, they take 6d10 psychic damage as their mind is flooded with infinity. They take no damage on a successful save. If the creature dies from this damage, their body is consumed and they vanish into the dreamscape, leaving only magical items behind. Once you use this feature, you can’t do so again until you finish a long rest.