Arch Artificer

Artificial Casting The artificer cannot lose concentration on spell effects from taking damage.

Legendary Resistance (3/day) Upon failing a saving throw, the artificer can choose to succeed.

Magitech Weapon The artificer's weapon attacks count as adamantine, silvered, and magical for the purpose of overcoming resistance. They can also use their intelligence modifier instead of using strength of dexterity for determining attack and damage rolls

Spellcasting. The artificer is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 19, +9 to hit with spell attacks). The artificer can cast disguise self and invisibility at will and has the following wizard spells prepared:

Cantrips (at will): fire bolt, light, mage hand, prestidigitation, shocking grasp

1st level (4 slots): absorb elements, identify, cure wounds, magic missile, thunderwave

2nd level (3 slots): detect thoughts, mind spike, mirror image

3rd level (3 slots): counterspell, fly, lightning bolt

4th level (3 slots): confusion, Evard's black tentacles, blight

5th level (3 slots): cone of cold, dominate person, modify memory

6th level (1 slot): chain lightning

7th level (1 slot): power word pain

Multiattack The artificer can cast a spell and make a glaive attack.

Magitech Glaive. Melee Attack: +10 to hit, reach 10 ft.  one target. Hit: 11 (1d10 + 5) slashing damage.

Counter Defense Whenever to artificer takes damage, it can use its reaction to command its bound construct to make a single weapon attack.

Movement (1 action) The artificer can move up to 30ft to a location that it can see within range.

Resilience (1 action) The artificer can end one spell effect or status condition on themselves.

Quick Strike (1 action) The artificer can make a melee weapon attack.

Cast a spell (2 actions) The artificer can cast a spell.