Immutable Form. The golem is immune to any spell or effect that would alter its form.
Magic Resistance. The golem has advantage on saving throws against spells and other magical effects.
Magic Weapons. The golem's weapon attacks are magical.
Regeneration: While the Pillars remain active, Trobriand recives 10 health per pillar per round
Multiattack. The golem makes two slam attacks.
Slam. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: (3d10 + 8) bludgeoning damage.
Spellcasting. Trobriand is an 18th-level spellcaster. His spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). He has the following wizard spells prepared:
Cantrips (at will): fire bolt, mage hand, prestidigitation
1st level (4 slots): detect magic, magic missile, shield
2nd level (3 slots): blur, detect thoughts, misty step, shatter
3rd level (3 slots): counterspell, dispel magic, fireball, haste
4th level (3 slots): blight, greater invisibility
5th level (3 slots): animate objects, Bigby's hand, scrying
6th level (1 slot): chain lightning, globe of invulnerability, True Seeing
7th level (1 slot): finger of death, forcecage
8th level (1 slot): incendiary cloud, power word stun
9th level (1 slot): power word kill
Slam (1 action) make a Slam attack
Cantrip (1 action) Use a Cantrip
Arcane Burst (2 actions) 10' area burst dealing 5d10 force damage (DC 20 for 1/2) then Makes a DC 20 WIS Save vs Disjuction (items and casting ability)
Pillar Buffs:
North Center - Truesight
South East - Haste
South West - Shield