Campaign: Dungeons of Drakkenheim

This focus is made from a refined delerium crystal encased in a glass orb. While holding it, you gain a +2 bonus to spell attack rolls and the saving throw DCs of your spells. In addition, you can use the crystal as a spellcasting focus.
  Once per day when you cast a spell of 5th level or lower, you may draw on the energy stored within the crystal to do so without expending a spell slot. If you do, you trigger a random arcane anomaly.

Arcane Anomalies (1d20)

1. Gravity breaks within a 100-foot radius area for 1 hour. Creatures Levitate in midair, and must move by pushing or pulling against a fixed object or surface within reach (such as a wall or a ceiling), which allows them to move as if they were climbing. Unattended objects float around randomly.
2. The nearest creature is affected by a Tasha's Hideous Laughter spell (Save DC 15) but instead of laughing, the creature repeats unfathomable combinations of syllables and words.
3. Time skips a beat. Creatures within 60 feet experience a palpable feeling of vertigo followed by a powerful sensation of déjà vu and are stunned for 1 round (No Save). 
4. The nearest creature becomes unstuck in time. It is affected by the Blink spell for 1 minute. Instead of vanishing into the Ethereal Plane, the creature vanishes into a sliver of time in its past or possible future.
5. A prismatic burst of energy erupts in a 20-foot radius. Creatures in the area must succeed on a DC 15 Constitution saving throw or take 8d6 radiant damage and become blinded for 1 round. The smell of ozone fills the area, and wood transforms into glass.
6. Echoes of possible realities are briefly visible for 1 minute. When a creature within 60 feet is hit by an attack, a faint vision of the creature being killed by that attack appears.
7. Discordant music fills the mind of all creatures within 30 feet, who are affected as if by Otto's Irresistible Dance (Save DC 15).
8. A section of stone, water, air, or energy becomes an appropriate delerium elemental.
9. An extraplanar creature is summoned and remains for 1 hour. The DM either chooses the creature or determines it randomly. It is friendly to the creature who triggered the anomaly.
10. All humanoid corpses within 120 feet animate as hostile haze husks. The shrieking undead beg frantically for forgiveness as they rip apart the living.
11. The shadows of 1d6 random creatures in the area animate and try to kill them. Once destroyed, the creatures don’t cast a shadow for 24 hours.
12. All creatures within 60 feet become invisible for 1 min or until they attack or cast a spell. 
13. Tendrils of life flow from the nearest creature to others. It must succeed on a DC 15 Constitution saving throw or take 8d8 necrotic damage, half on a success. The three nearest creatures within 60 feet each regain hit points equal to the damage taken.
14. A Hypnotic Pattern (Save DC 15) appears. It creates scintillating impossible colours in shapes which are simply wrong. Creatures incapacitated by the spell weep uncontrollably.
15. An Evard's Black Tentacles spell appears in the area for 1 hour (Escape DC 15).
16. Objects within 60 feet come to life for the next hour, as if affected by the Animate Objects spell. They mumble awful truths, but are not otherwise hostile. 
17. The nearest creature is polymorphed into an awakened shrub for 1 hour or until reduced to 0 hp (No Save).
18. Time slows down for up to six randomly determined creatures within 120 feet of the anomaly. They are affected by the Slow spell for 1 minute. (Save DC 15).
19. Time speeds up for one randomly determined creature within 60 feet of the anomaly. They are affected by the Haste spell for 1 minute.
20. A bowl of flowers and a very surprised aquatic mammal appear 100 feet in the air. "Oh no, not again..." thinks the flowers.

Notes: Bonus: Spell Attacks, Bonus: Spell Save DC, spellcaster, Buff, Focus