Devils Sight. Magical darkness doesn't impede the devils darkvision. Magic Resistance. The devil has advantage on saving throws against spells and other magical effects.
Multiattack. The devil makes two attacks, one with its horns and one with its switch. Horns. Melee Weapon Attack: +5 to hit, reach 5ft., one target. Hit 10 (2d6+3) piercing damage. Switch. Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit 8 (2d4+3) slashing damage. Ice Wall (recharge 6). The devil magically forma 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. When the wall appears, each creature in its space is pushed out of it by the shortest rout possible. The creature chooses which side of the wal to end up on unless the creature is incapacitated. The creature chooses which side of the wall to end up on, unless the creature is incapacitated. The creature then makes a DC 14 Dexterity saving throw, taking 17 (5d6) cold damage on a failed save, or half as much damage on a successful one. The wall lasts for 1 minute or until the devil is incapacitated or dies. The wall can be damaged and breached; each 10-foot section has AC 5, 15 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 finished moving through the frigid air on a turn, willingly or unwillingly, the creature must make a DC 14 constitution saving throw, taking 10 (3d6) cold damage on a failed save and half as much on a successful one. The frigid air dissipates when the rest of the wall vanishes.
Krampus can make one legendary action, choosing from the options below. A legendary action may only be used at the end of another creatures turn. Krampus regains spent legendary actions at the start of its turn. Attack. Krampus makes one horn attack. Ice Field. If krampus has one or more ice walls in effect, he may choose one and cause ice shards to sprout from the ground in a 30 foot long field beginning on one side of the wall. All creatures in the field take 2 (1d4) piercing damage.
On initiative count 20 (losing initiative ties), Krampus can take a lair action to cause one of the following effect; he can't use the same effet two rounds in a row: -Krampus casts entangle, causing holly plants to spring from the ground -Krampus causes a 10ft square of ground he can see in his lair to be covered in ice. The ice lasts for one minute or until it is melted with fire. Any creature on the ice when it appears must succeed on a DC 14 Dexterity saving throw or be knocked prone and slide 10 feet in a random direction determined by a d8 roll. When a creature enters the area for the first time or ends it's turn there it must make the same save. The ice patch has AC 5, 15 HP, vulnerability to fire damage, and immunity to acid, cold, necrotic, poison, and psychic damage. -Krampus causes an icicle to fall from the ceiling of his lair landing on and filling any 5 ft square in the lair he can see. The icicle is a 5 ft circle and 10 feet tall. Any creature in the area when it falls is pushed out of it by the shortest rout possible. The creature chooses which square to end up in unless the creature is incapacitated. The creature then makes a DC 14 Dexterity saving throw, taking 5 (1d10) bludgeoning damage on a failed save, or half as much damage on a successful one.