Arcane Preserver

Legendary Resistance (5/day). If the Arcane Preserver fails a saving throw it can choose to succeed instead.

Magic Resistance: The Arcane Preserver has advantage to saving throws against spells and magical effects.

Adamantine Plate: The Arcane Preserver is made of pure adamantine, any critical hit against it becomes a normal hit.

Immutable Form: The Arcane Preserver is immune to any spell or effect that would alter its form.

Magic Weapons. The Arcane Preserver's weapon attacks are magical.

Arcane Surge: At the start of each of the Arcane Preserver's turns it emits a blast of force energy from itself in a 40ft radius, each creature in range takes 1d6 force damage. This damage increases by 1d6 each time the Arcane Preserver makes a successful saving throw by 5 or more against a spell or magical effect up to a maximum of 6d6 force damage (the use of a legendary resistance does not trigger this effect). The surge then resets.

Multiattack. The Arcane Preserver makes two arcane fist attacks or uses its Manus Ray.

Arcane Fist. Melee Weapon Attack: +16 to hit; 10ft reach., one target. Hit: 4d10+7 force damage. If the target is a creature, it must succeed on a DC 21 Strength saving throw or be pushed up to 20ft away and knocked prone.

Manus Ray. Ranged Spell Attack: +16 to hit; 120ft range., one target. Hit: 8d8+7 force damage. This attack ignores all forms of cover except total cover.

Arcane Torrent (Recharge 5 or 6). An torrent of energy blasts out from the Arcane Preserver in a 100ft long 5ft wide line in a direction it chooses. Each creature within the line must make a DC 21 Dexterity saving throw, taking 20d6+30 force damage on a failed save and half as much on a successful save. If a creature is reduced to 0 hit points in this way, it is disintegrated. 

Counterspell: The Arcane Preserver attempts to interrupt a creature that it can see within 60ft in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, the Arcane Preserver makes an Intelligence check with a DC equal to 10 + the spell's level. On a success, the creature's spell fails and has no effect.

The Arcane Preserver can take 3 legendary actions, choosing from the list below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The Arcane Preserver regains spent legendary actions at the start of its turn.

• Attack (1 action): The Arcane Preserver makes one Arcane Fist attack or uses its Manus Ray.
• Teleport (2 action): The Arcane Preserver magically teleports, along with any equipment it is wearing or carrying up to 120ft to an unoccupied space it can see.
• Arcane Orb (3 actions). The Arcane Preserver unleashes a violent crackling orb of energy at a point it chooses within 150ft. Each creature in a 20ft radius sphere centered on that point must make a DC 21 Dexterity saving throw. A target takes 10d6 force damage on a failed save or half as much damage on a successful one. The blast from the orb leaves behind an arcane void, nullifying all spells and magical effects, except those created by an artifact or deity until the end of the Arcane Preserver's next turn.