I'm about to run a Wizard tower. I really wanted to run a Living Spellbook from Redditor /u/StoneStrix but had to scale it down. Since low level spellcasters are kind of hard to find, I thought an Elemental could be appropriate as a baseline for this monster.
It will be the final encounter of a one-shot for four 6th-level players (not an optimal party, no power-gamers). The party members are a barbarian (Ancestral Guardian XGE), fighter (Battlemaster), artificer(Gunsmith) and a Storm sorcerer. The fighter and the barbarian are having +1 weapons. We homebrewed some healing into the Storm sorcerer, he knows healing spirit.
The encounter will contain: 1 Living Spellbook + 1-2 Swarms of flying Books .
Living Spellbook
Medium construct, unaligned
Armor Class 14 (17 with mage Armor)
Hit Points 90
Speed 30 ft., fly 30 ft.
STR | DEX | CON | INT | WIS | CHA
12 (+1)|18 (+4)|14 (+2)|14 (+2)|10 (+0)|1 (-5)|
Damage Immunities poison, psychic
Damage Resistances bludgeoning, piercing and slashing damage from nonmagical weapons
Damage Vulnerabilities fire
Condition Immunities charmed, exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses blindsight 120 ft., passive Perception 10
Languages -
Challenge 5
Immutable Form. The spellbook is immune to any spell or spell effect that would alter its form.
Magic Resistance. The spellbook has advantage on saving throws against spells and other magical effects.
Mage Armor. The Spellbook has a permanet Mage Armor on it, wich can't be recasted.
--Actions--
Multiattack. The Living Spellbook makes two Paper cut attacks.
Paper Cut. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft., or range 30/60 ft., one creature. Hit: 13 (2d8+4) slashing damage4) slashing damage.
Arcane Explosion (Recharge 4-6). Each creature within 10 ft. of the Spellbook must make a DC 13 Strength saving throw. On a failure, a target takes 15 (3d8 + 2) bludgeoning damage and is pushed 10 feet away from the Spellbook and knocked prone. If the saving throw is successful, the target takes half the bludgeoning damage and isn't flung away or knocked prone.
Swarm of flying Books
Medium swarm of tiny monstrosities, unaligned
Armor Class 13
Hit Points 28
Speed fly 30 ft.
STR | DEX | CON | INT | WIS | CHA
13 (+1)|16 (+3)|9 (-1)|1 (-5)|7 (-2)|2 (-4)|
Damage Resistances bludgeoning, piercing and slashing damage from nonmagical weapons
Condition Immunities charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Senses darkvision 60 ft., passive Perception 8
Languages -
Challenge 1 (200 XP)
Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny book.The swarm can't regain hit points or gain temporary hit points.
--Actions--
Bite. Melee Weapon Attack: +5 to hit, one creature. Hit: 14 (4d6) piercing damage Or 7 (2d6) piercing damage if the swarm has half of its hit points or fewer.