Clockwork Mage

Immutable Form. The Clockwork Mage is immune to any spell or effect that would alter its form. 

Magic Resistance. The Clockwork Mage has advantage on saving throws against spells and other magical effects. 

Magic Weapons. The Clockwork Mage's weapon attacks are magical.

Silent Caster. The Clockwork Mage doesn't need verbal components to cast spells. 

Quickened Cast. When the Clockwork Mage casts a spell that has a casting time of 1 action, it may instead change the casting time to 1 bonus action. 

Wand Magic. The Clockwork Mage's crystal wand allows it to cast spells, requiring no material components. Its spellcasting ability is Wisdom(spell save DC 15, +7 to hit with spell attacks). The arcane school of the wand determines the color of the crystal and the spells:

1. Abjuration(Blue):

• At will: Absorb Elements, Shield
• 3/day each: Lesser Restoration, Pass Without Trace
• 1/day: Counterspell

2. Conjuration(Orange):

• At will: Entangle, Grease
• 3/day each: Misty Step, Web
• 1/day: Stinking Cloud

3. Enchantment(Yellow):

• At will: Bane, Sleep
• 3/day each: Crown of Madness, Hold Person
• 1/day: Confusion

4. Evocation(Red):

• At will: Magic Missile, Thunderwave
• 3/day each: Gust of Wind, Scorching Ray
• 1/day: Fireball

5. Illusion(Purple):

• At will: Color Spray, Disguise Self
• 3/day each: Blur, Invisibility
• 1/day: Hypnotic Pattern

6. Necromancy(Black):

• At will: Inflict Wounds, Ray of Sickness
• 3/day each: Blindness/Deafness, Ray of Enfeeblement
• 1/day: Bestow Curse

7. Transmutation(Green):

• At will: Expeditious Retreat, Catapault
• 3/day each: Enlarge/Reduce, Spider Climb
• 1/day: Haste

Multiattack: The Clockwork Mage makes four Slam attacks. 

Slam: Melee weapon attack, +6 to hit, reach 5ft, one target. Hit 12(3d6+2) bludgeoning damage. 

Arcane Conversion(Recharge 6): The Clockwork Mage uses its magical abilities to change the arcane school of its crystal wand. Roll a d6 to determine the new school, removing the current one from the list of possibilities. The Clockwork Mage regains the use of all its spells.