Arcane Caretaker

Magic Resistance. The helmed horror has advantage on saving throws against spells and other magical effects.

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

Multiattack. The Arcane Caretaker makes two longsword attacks.

Longsword. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) slashing damage.

Runic Transport. Steps on a rune on the floor, and reappears at another rune.

Bookcase Shove. A bookcase lurches forward. One creature within 30 feet of a bookshelf must succeed on a DC 15 DEX save or be restrained by animated scrolls and books (escape DC 15 on their turn). Effect lasts until the start of the Caretaker’s next turn.

Spell Reflection. Once per turn, when the Arcane Caretaker is targeted by a spell that affects only it (no area or multiple targets), it can use its reaction to reflect the spell back at the caster. The original caster becomes the target, using their own spell save DC and attack bonus. The Caretaker must be aware of the spell to reflect it.

Suppress Magic. The Caretaker targets one creature it can see within 60 feet. The target must succeed on a DC 15 Constitution saving throw or lose concentration on a spell being maintained. On a failure, the node cannot be activated until the next round.