Weird cubes of unknown origin and weird powers. Every cube looks different and gives the holder different powers.
Creature that holds the cube in its bare hand(s) is “the holder” and can perform the abilities of the cube. There can only be one holder. If second person grabs the cube, he/she does not get the effect until first person lets go.
Spells cast via cube have DC 15 and +7 to hit. Their cooldowns are tied to the cube, not to the holder. Any cast spells via cube dispell themselves when caster looses contact with the cube or becomes unconscious
Cubes are quite large and their weight is very weirdly balanced. That makes it very hard for a person to hold it in one hand. Creature must hold it in both hands unless it uses “Hold in One Hand” action
Pick Up
Because cube is so cumbersome to hold, it takes a whole action to pick it off the ground
Hold in One Hand
Attempt to balance the cube on one hand. Make DEX check, DC 9.
On successful check, you successfully manage to balance the weight of the cube on just one hand. Until the start of your next turn, your other hand is free.
On failed check, cube falls to the ground.
If you receive any damage while holding the cube in one hand, make DEX saving throw. The DC equals 8 or half the damage you take, whichever number is higher. If you fail the save, cube falls to the ground.
Cube constantly glows with very bright white light. It does NOT light up its surroundings, but cube itself is easily spotted from 300ft in any conditions (including magic darkness). Despite that, it does not hurt your eyes when looking at it.
Fullbright vision
Holder of the cube sees its surroundings in bright light as if it was under the sun under any condition (including magic darkness).
Light
You touch one object. Until the spell ends, the object sheds bright light in a 20-foot radius and dim light for an additional 20 feet. The light can be colored as you like. Completely covering the object with something opaque blocks the light. The spell ends if you cast it again or dismiss it as an action.
If you target an object held or worn by a hostile creature, that creature must succeed on a Dexterity saving throw to avoid the spell.
Total number of created lights is not limited.
Blinding Light
Cube momentarily flashes with blinding light. Any creature (except the holder) within 30ft line of sight of the cube must make constitution saving throw. On a failed save, creature becomes blinded for 1 minute. A blinded creature can make a Constitution saving throw at the end of each of its turns, ending the effect on itself on a success.
If a creature knew one turn in advance that spell will be triggered, it can expend its reaction to close its eyes right before spell triggers. This allows it to make initial CON save with advantage.
Spell can only be cast once per minute.
Surface of the cube is so dark that it appears like a cube-shaped hole, not a solid object.
Light Suction
Cube sucks light from surrounding area. Any space within 30 feet of the cube becomes dim light (or darkness if area was already dim light before).
Maddening Darkness
Duration: up to 1 minute
Magical darkness spreads from a center of the cube to fill a 60—foot—radius sphere until the spell ends. The darkness spreads around corners. A creature with darkvision can’t see through this darkness. Nonmagical light, as well as light created by spells of 5th level or lower, can’t illuminate the area.
At the end of each of its turns, caster can decide whether to activate or deactivate maddening effect. When active, shrieks, gibbering, and mad laughter can be heard within the sphere, originating from the cube. Whenever a creature starts its turn in the sphere, it must make a Wisdom saving throw, taking 2d8 psychic damage on a failed save, or half as much damage on a successful one. After taking the damage, if creature can hear, it knows the exact position of the cube to the point where it can attack its holder without disadvantage, until holder moves.
Holder can see through the darkness and it’s immune to its effects.
Holder can tell any creature that sound effects are only an illusion. If creature believes the holder, it can make wisdom throws from the darkness with advantage.
Spell can only be cast once per minute.