Sources
CR
Type
Size
Alignment
Movement

Zegana

Medium Humanoid (merfolk), Lawful Neutral

Armor Class 16 (natural armor)
Hit Points 130 (20d8 + 40)
Speed 30 ft., swim 40 ft.
STR
11
+0
DEX
14
+2
CON
14
+2
INT
20
+5
WIS
18
+4
CHA
16
+3
Saving Throws INT +10, WIS +9
Skills Insight +9, Nature +10, Perception +9
Damage Resistances cold, poison
Senses darkvision 60 ft., passive Perception 19
Languages Common, Elvish, Merfolk
Challenge 16 (15,000 XP)

Traits

Amphibious. Zegana can breathe air and water.

Legendary Resistance (3/Day). If Zegana fails a saving throw, she can choose to succeed instead.

Magic Resistance. Zegana has advantage on saving throws against spells and other magical effects.

Spellcasting

Spellcasting. Zegana is a 15th-level Simic spellcaster. Her spellcasting ability is Intelligence (spell save DC 18, +10 to hit with spell attacks). She has the following wizard spells prepared:

Cantrips (at will): acid splash, druidcraft, ray of frost, shape water

1st level (4 slots): color spray, expeditious retreat, fog cloud, shield

2nd level (3 slots): enlarge/reduce, gust of wind

3rd level (3 slots): counterspell, fly, slow

4th level (3 slots): control water, ice storm, polymorph

5th level (2 slots): conjure elemental, creation

6th level (1 slot): move earth, wall of ice

7th level (1 slot): prismatic spray, teleport

8th level (1 slot): control weather, dominate monster

Actions

Prime Speaker's Trident. Melee or Ranged Weapon Attack: +10 to hit, reach 5 ft. or range 20/60 ft., one target. Hit:12 (2d6 + 5) piercing damage, and the trident emits a thunderous boom. Each creature in a 15-foot cube originating from the prongs of the trident must make a DC 18 Constitution saving throw. On a failed save, the creature takes 9 (2d8) thunder damage and is pushed 10 feet away from Zegana. If the creature is underwater, the damage is increased to 13 (3d8). On a successful save, the creature takes half as much damage and isn't pushed.

Deluge (Recharge 4–6). Zegana conjures a wave of water that crashes down on an area within 120 feet of her. The area can be up to 30 feet long, up to 10 feet wide, and up to 10 feet tall. Each creature in that area must make a DC 18 Dexterity saving throw. On a failed save, a creature takes 18 (4d8) bludgeoning damage and is knocked prone. On a successful save, a creature takes half as much damage and isn't knocked prone. The water spreads out across the ground, extinguishing unprotected flames it comes in contact with, and then vanishes.

Legendary Actions

Adaptive Skin. Zegana gains resistance to one damage type of her choice-acid, fire, lightning, or thunder-until the start of her next turn.

Trident. Zegana makes one melee attack with the Prime Speaker's Trident.

Enlarge (Costs 2 Actions). Zegana casts enlarge/reduce on herself, using the enlarge option, without expending a spell slot.

Deluge (Costs 3 Actions). Zegana uses Deluge, if available.

Lore

The regal and reticent Prime Speaker Zegana is the merfolk guildmaster of the Simic Combine. She upholds the traditional ways of the guild and its utopian philosophy, which espouses a vision of an ideal world in which nature and civilization coexist in perfect balance. Some people in the guild-members of the Adaptationist faction in particular-argue that her ways are outdated and the guild requires more practical leadership. In response, Zegana maintains that she serves as prime speaker only at…