Arcane Contraption

A fist sized stone sphere, with many magical inscriptions upon it. When activated, the sphere grows larger, as parts of the mechanisms cause the glyphs and stone plates to widen. Depending on the school of the contained spell, the glyphs and light it emanates changes in color.
Arcane Contraption has an AC of 20, 30 health points, resistance against spell damage, immunity to psychic and poison damage, and a damage threshold of 5. If it's health points are reduced to 0, roll a d20. On a roll of of 1, it explodes and is permanently lost, otherwise it instead reduced to 1 hit point. Casting Mending on the Arcane Contraption restores all of it's hit points.
The rarity of the Arcane Contraption depends on the level of the contained spell, it cannot contain a spell of 9th level.
  1-2 = Uncommon;
  3-4 = Rare;
  5-6 = Very Rare;
  7-8 = Legendary;
You can attune to a number of Arcane Contraptions equal to your proficiency bonus + Intelligence modifier using the same attunement slot. Each Arcane Contraption counts as a number of Arcane Contraptions equal to the level of the contained spell for the purposes of attunement. You cannot use multiple attunement slots to attune to a single Arcane Contraption.
If you change the contained spell, you unattune from the item and must attune again, you can do so during the same long rest.

Spell Container: The Arcane Contraption contains a single non-cantrip spell from the wizard spell list. If you have proficiency with the Arcana skill and the Spellcasting or Pact Magic feature, you can permanently change the spell it contains with another one during a long rest by expending a spell slot of a level equal to the base level of the spell. The new spell cannot be a cantrip, must be from the wizard spell list and from the same spell school as the one it currently contains.

Produce Spell: Once per long rest, as an action, you can activate the contraption, then throw it up to 60 feet from you or keep it on your person. Any creature that can touch the sphere can use its action to throw or pick it up.
At the start of your next turn, the Arcane Contraption casts the contained spell at its base level, centered on itself. If the contained spell targets creatures it targets the maximum possible number of creatures it can that are closest to it. If the contained spell targets a cone or line, it does so in the opposite direction from the one it was thrown in, if it is held by a creature, it can choose in which direction the spell is cast. If a spell has options or an ongoing effect you can activate, it acts as already programmed when you attuned to it or how you choose for it to act when you change the spell it contains.
It uses your ability scores, spell attack modifier(your proficiency bonus + your intelligence modifier), and spell save DC(8 + your proficiency bonus + your intelligence modifier). Whenever it has to make a concentration check(if the spell it is producing requires concentration) it makes one as if you are making it.