Mirror knights are usually created not soley for their power over the mirror to which they are bound, but in order to guard mirrors that already have other powers. The binding is easier when there already magic in the mirror, and the knight is too expensive to create with some great purpose.
Masters of Another World. The mirror knight can use its mirror for its own magic beyond the magic of the mirror itself. It commands a shadow realm to which the mirror can be a window where it can trap foes or from which it can summon shadow beings of those previously trapped. Creatures captured in this realm can see previously captured creatures transformed into shadow beings, waiting to be summoned.
Mirror Union. A mirror knight necessarily bears a resemblance to the mirror with which it is bound. It is made mostly if the same material as the frame.
Large construct, lawful neutral
Armor Class: 20 (natural armor, shield)
Hit Points: 68 (8d10+24)
Speed: 20 ft.
|19 (+4)||11 (+0)||16 (+3)||10 (+0)||10 (+0)||10 (+0)|
Skills: Perception +4
Damage Resistances: bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities: poison, necrotic
Condition Immunities: blinded, charmed, deafened, frightened, paralyzed, petrified, poisoned, stunned
Senses: blindsight 30 ft., truesight 120 ft. cone, passive Perception 12
Languages: understands the languages if its creator but can’t speak.
Challenge: 5 (1,800 XP)
Magic Resistance. The mirror knight has advantage on saving throws against spells and other magical effects.
Truesight Cone. The mirror knight has truesight in a 120-foot cone where its shield is facing. At the start of each of its turns, the mirror knight decides which way the cone faces.
Multiattack. The mirror knight makes a longsword attack and either a Capture or Summon action.
Longsword. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8+4) slashing damage.
Capture. The mirror knight moves up to its speed. While doing so, it can enter Medium or smaller creatures’ spaces. Whenever the knight enters a creature’s space, the creature must make a DC 15 Dexterity saving throw.
On a successful save, the creature can choose to be pushed 5 feet back or to the side of the knight. A creature that chooses not to be pushed suffers the consequences of a failed saving throw.
On a failed save, the knight enters the creature’s space, and the creature takes 10 (3d6) force damage and is captured in the shield. The captured creature is blinded (except for where the knight’s truesight cone is directed) and restrained, it has total cover against attacks and other effects outside the mirror microcosm, and it must make a DC 11 saving throw at the start of each of the knight’s turns. If it fails its save three times it permanently becomes shadow being trapped in the mirror with no will of its own. The failures don’t need to be consecutive; keep track of failures until the creature has three.
A captured creature can try to escape by taking an action to make a DC 14 Wisdom check at disadvantage. On a success, the creature escapes and enters a space of its choice within 5 feet of the knight. If the mirror knight is killed, captured shadow beings cease to be. Living creatures in the mirror appear in its space and take 14 (4d6) force damage.
Summon. The mirror knight plants its shield and calls forth a shadow being from within the mirror that appears 5 feet from it in the direction of the truesight cone. These shadow beings can be any medium or smaller creature that the mirror knight can have reasonably captured previously, retaining their prior stat blocks except gaining resistance to bludgeoning, piercing, and slashing from nonmagical attacks and vulnerability to radiant damage. Below is a table for determining CR 1 and lower random shadow beings.
When the mirror knight is killed, its shadow beings disappear.
|Roll (1d20)||Creature||CR (XP)|
|1||Commoner||0 (10 XP)|
|2||Cultist||1/8 (25 XP)|
|3||Kobold||1/8 (25 XP)|
|4||Noble||1/8 (25 XP)|
|5||Tribal Warrior||1/8 (25 XP)|
|6||Arakocra||1/4 (50 XP)|
|7||Bullywug||1/4 (50 XP)|
|8||Drow||1/4 (50 XP)|
|9||Goblin||1/4 (50 XP)|
|10||Winged Kobold||1/4 (50 XP)|
|11||Gnoll||1/2 (100 XP)|
|12||Hobgoblin||1/2 (100 XP)|
|13||Lizardfolk||1/2 (100 XP)|
|14||Orc||1/2 (100 XP)|
|15||Scout||1/2 (100 XP)|
|16||Thug||1/2 (100 XP)|
|17||Bugbear||1 (200 XP)|
|18||Goblin Boss||1 (200 XP)|
|19||Half-ogre||1 (200 XP)|
|20||Spy||1 (200 XP)|
On Saturday, the Haven players fought one of these, but the Mind Weave version had so much more health at a similar challenge level. I’ve always thought the Looking Glass Knight from Dark Souls 2 would be a great enemy, and it just made sense for alchemist gnomes with no true magic to use something like this as a guardian.