Hollow King
Traits
Magic Resistance. Advantage on saving throws.
Hollow Crown. The Hollow King is considered Invisible for as long as it remains unseen. It becomes visible when it attacks; it can become Invisible again with a Bonus Action (see Vanish).
Regal Ambush. The first attack the Hollow King makes from Invisible deals 27 (6d8) extra Psychic damage.
Fey Step Aversion. The Hollow King cannot use Vanish while in Bright Light.
Actions
Multiattack. The Hollow King makes three Crown Blade attacks.
Crown Blade. Melee Attack Roll: +11, reach 5 ft. Hit: 17 (2d10 + 6) Slashing damage plus 9 (2d8) Psychic damage.
Hollow Gaze (Recharge 5–6). Wisdom Saving Throw: DC 18, every creature that can see the Hollow King within 60 feet.
- Failure: 36 (8d8) Psychic damage, and the target has the Frightened condition for 1 minute. A Frightened target also cannot see the Hollow King (it is considered Invisible to that target). The target can repeat the save at the end of each of its turns.
- Success: Half damage.
Bonus Actions
Vanish. The Hollow King becomes Invisible and spends half its movement to move without provoking Opportunity Attacks.
How to Use
Turn-one math: 3 × (17 + 9) + 27 ambush = 105 damage. That kills a Lv14 Rogue in a single turn.
Hollow Gaze is deviously cruel: a Frightened target can no longer see it — meaning a second ambush is all but guaranteed.
Key
Bright Light (Vanish doesn't work) plus Truesight/See Invisibility. And immunity to Frightened (a Paladin's aura) neutralizes this monster by half.