School of the Arcane Horizon (5A)

This is a Wizard arcane tradition for 5A.

Source: Mike Myler in En5ider 147 under the name School of the Inside Out.

Since the dawn of time, mages and priests have pursued ancient secrets revealing the fabric of reality, suffering eternally for their hubris. The school of the arcane horizon has proceeded further than most, unlocked a path to forbidden arcana otherwise shrouded in mystery.

Psionic Subclasses

In 5E, psionics does not have its own classes, it is instead expressed through subclasses. The this subclass uses psionic powers, along with a number of other subclasses in the game, the artificer Archivist and Psychometrist, bard College of Whispers and Psychic, cleric Spiritualist, fighter Psi Warrior, monk Way of the Soft Whisper, Spiral Monk, rogue Soulknife, sorcerer Aberrant Mind and Mystic, and wizard Arcane Horizon and Mentalist.

Arcane Tradition Features

Disorient Senses

Starting at 2nd level, you learn the secrets of what lies behind the veil of reality. As an action, you pull away the curtain of existence to disturb a single creature within 30 feet. If the target can see you, it must succeed on an Intelligence saving throw against your wizard spell save DC or be unhinged for a number of rounds equal to your proficiency bonus. An unhinged creature is allowed a new Intelligence saving throw at the end of its turns to end the effect. A unhinged creature loses any types of vision other than regular vision (a creature without regular vision is blinded). Attack rolls against the creature have advantage, and the creature’s attack rolls and ability checks have disadvantage.

Once the effect ends, or if the creature succeeds on its initial saving throw against this effect, you can’t use this feature on that creature again until you finish a short rest.

Inverted Psyche

At 6th level, you gain resistance to psychic damage. In addition, you can communicate telepathically with any creature you can see within 30 feet of you. You don’t need to share a language with the creature for it to understand your telepathic utterances, but the creature must be able to understand at least one language.

Occult Secrets

Beginning at 10th level, you gain advantage on Intelligence saving throws, Intelligence (Arcana) checks, and Intelligence (Religion) checks.

Otherverse Disjunction

Starting at 14th level, you can use this feature to instantly transport a creature within 30 feet to a place both within and outside of reality. The creature makes an Intelligence saving throw against your spell save DC or disappears and shudders across the underpinning matrix of existence for a number of rounds equal to your proficiency bonus. If the target is not an aberration, it takes 3d10 psychic damage at the end of each of its turns as it reels from its horrific experience. After this the creature is allowed an Intelligence saving throw to end the effect. On a success the creature returns to the space it previously occupied (or the nearest unoccupied space) and is unhinged, as Disorient Senses above. Once you use this feature, you can’t use it again until you finish a long rest.

Editor's Notes

Cosmic horror can be surprisingly easy to implement.