actions

Claw (Fiend Form Only). Melee Attack: +5 to hit, reach 5 ft., one target. Hit: 1d6 + 3 slashing damage.
Charm. One humanoid the fiend can see within 30 feet of it must succeed on a DC 14 Wisdom saving throw or be magically charmed for 1 day. The charmed target obeys the fiend’s verbal or telepathic commands. If the target suffers any harm or receives a suicidal command, it can repeat the saving throw, ending the effect on a success. If the target successfully saves against the effect, or if the effect on it ends, the target is immune to this fiend’s Charm for the next 24 hours.
The fiend can have only one target charmed at a time. If it charms another, the effect on the previous target ends.
Draining Kiss. The fiend kisses a creature charmed by it or a willing creature. The target must make a DC 14 Constitution saving throw against this magic, taking 32 (5d10 + 5) psychic damage on a failed save, or half as much damage on a successful one. The target’s hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.
Etherealness. The fiend magically enters the Border Shadow from the Mortal Plane, or vice versa.

actions

Multiattack. The ice fiend makes three attacks: one with its bite, one with its claws, and one with its tail.
Bite. Melee Attack: +8 to hit, reach 5 ft., one target. Hit: 2d6+5 piercing damage plus 4d6 cold damage.
Claws. Melee Attack: +8 to hit, reach 5 ft., one target. Hit: 2d4+5 slashing damage plus 4d6 cold damage.
Tail. Melee Attack: +8 to hit, reach 10 ft., one target. Hit: 2d6+5 piercing damage plus 4d6 cold damage.
Wall of Ice (Recharge 6). The fiend magically forms an opaque wall of ice on a solid surface it can see within 60 feet of it. The wall is 1 foot thick and up to 30 feet long and 10 feet high, or it’s a hemispherical dome up to 20 feet in diameter.
When the wall appears, each creature in its space is pushed out of it by the shortest route. The creature chooses which side of the wall to end up on, unless the creature is incapacitated. The creature then makes a DC 15 Dexterity saving throw, taking 35 (10d6) cold damage on a failed save, or half as much damage on a successful one.
The wall lasts for 1 minute or until the fiend is incapacitated or dies. The wall can be damaged and breached; each 10-foot section has AC 5, 30 hit points, vulnerability to fire damage, and immunity to acid, cold, necrotic, poison, and psychic damage. If a section is destroyed, it leaves behind a sheet of frigid air in the space the wall occupied. Whenever a creature finishes moving through the frigid air on a turn, willingly or otherwise, the creature must make a DC 15 Constitution saving throw, taking 17 (5d6) cold damage on a failed save, or half as much damage on a successful one. The frigid air dissipates when the rest of the wall vanishes.
For purposes of unbind, this counts as a spell of aether cost 12.

actions

Multiattack. The flame fiend makes two attacks: one with its longsword and one with its whip.
Longsword. Melee Attack: +10 to hit, reach 10 ft., one target. Hit: 3d8+8 slashing damage plus 3d8 lightning damage. If the flame fiend scores a critical hit, it rolls damage dice three times, instead of twice.
Whip. Melee Attack: +10 to hit, reach 30 ft., one target. Hit: 2d6+8 slashing damage plus 3d6 fire damage, and the target must succeed on a DC 17 Strength saving throw or be pulled up to 25 feet toward the flame fiend.
Teleport. The flame fiend magically teleports, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see.
Fire Aura. As a bonus action, the flame fiend makes each creature within 5 feet of it takes 10 (3d6) fire damage, and flammable objects in the aura that aren’t being worn or carried ignite.