Walter can spend up to 10 ki points to deal 2d10 necrotic damage per ki point to a creature within 5 feet, subject to a Constitution saving throw.

As an action, Walter can force each creature of his choice within 30 feet that can see him to make a Wisdom saving throw or become frightened until the end of his next turn.

Walter spends 1 ki point to make two additional unarmed strikes as a bonus action.

Walter spends 2 ki points to take the Dodge action as a bonus action.

Walter spends 1 ki point to Dash or Disengage as a bonus action, and his jump distance is doubled for the turn.

Walter can use Dexterity instead of Strength for monk weapon and unarmed strike attacks. His unarmed strikes deal 1d10 damage at 20th level, and he can make an unarmed strike as a bonus action after attacking with an unarmed strike or monk weapon.

His speed increases by 20 feet while unarmored and without a shield. He can also use Step of the Wind to Dash or Disengage as a bonus action, and his jump distance doubles when used.

Walter can use a reaction to reduce ranged weapon damage by 1d10 + 28, catching the missile if the damage is reduced to 0.

Walter can spend 1 ki point to remain at 1 hit point instead of dropping to 0 hit points.

Walter makes two attacks with his fangs as part of the Attack action, with each unarmed strike dealing 1d10 + 8 bludgeoning damage before other modifiers.

Walter spends 1 ki point after hitting with a melee weapon attack to force a Constitution saving throw against ki save DC 19 or stun the target.

While unarmored and not wielding a shield, Walter's AC equals 10 + his Dexterity modifier. His extreme physical control gives him AC 18 under this character build's specified calculation.

Walter has 20 ki points, regained after a short or long rest. Ki powers Flurry of Blows, Patient Defense, Step of the Wind, and other monk features. His ki save DC is 19.

Walter follows the Way of the Long Death, a tradition focused on studying fear, mortality, and the exact instant life becomes death.

When Walter reduces a creature within 5 feet to 0 hit points, he gains temporary hit points equal to 5 + his Wisdom modifier, or 10 temporary hit points with his current Wisdom.

When Walter is hit by a ranged weapon attack, he can use his reaction to reduce the damage by 1d10 + 20 + his Dexterity modifier. If he reduces the damage to 0, he can catch the missile and spend 1 ki point to make a ranged attack with it.

Walter gains the Ability Score Improvement feature at 4th, 8th, 12th, 16th, and 19th level. His ability scores are already established by the requested concept, so these improvements are represented as exceptional natural ability rather than additional changes.

Walter can use his reaction to reduce falling damage by 100 points, allowing him to survive and control falls that would kill ordinary people.

Walter can attack twice, instead of once, whenever he takes the Attack action on his turn.

When Walter hits another creature with a melee weapon attack, he can spend 1 ki point to force a Constitution saving throw. On a failure, the target is stunned until the end of Walter's next turn.

Walter's unarmed strikes count as magical for overcoming resistance and immunity to nonmagical attacks and damage.

Walter takes no damage on a successful Dexterity saving throw against an effect that normally deals half damage, and only half damage on a failed save. He also suffers no damage from successful area-effect Dexterity saves.

Walter can use his action to end one effect causing him to be charmed or frightened.

His unarmored movement increases to a total speed of 50 feet. He can also move along vertical surfaces and across liquids during his turn without falling during the movement.

Walter is immune to disease and poison.

Walter can understand all spoken languages, and any creature that understands a language can understand his speech.

Walter gains proficiency in all saving throws. If he fails a saving throw, he can spend 1 ki point to reroll it and must use the new result.

Walter no longer suffers the frailty of old age, cannot be magically aged, and no longer needs food or water.

Walter can move along vertical surfaces and across liquids during his turn without falling, and his unarmored movement allows him to cross any distance that his 50-foot speed can cover.

Walter can spend 4 ki points to become invisible for 1 minute and gain resistance to all damage except force damage. He can also spend 8 ki points to cast Astral Projection without material components.

When Walter rolls initiative and has no ki points remaining, he regains 4 ki points.

When Walter reduces a creature to 0 hit points, he gains 10 temporary hit points. These temporary hit points can accumulate only according to normal temporary hit point rules.

Walter can frighten nearby creatures with an overwhelming display of controlled menace, forcing creatures within 30 feet that can see him to make a Wisdom saving throw.

When Walter would be reduced to 0 hit points, he can spend 1 ki point to drop to 1 hit point instead. He can do this repeatedly as long as he has ki.

Walter can touch a creature within 5 feet and spend 1 to 10 ki points. The target must make a Constitution saving throw, taking 2d10 necrotic damage per ki point spent on a failure, or half as much on a success.

Walter has a reliable network of informants, smugglers, fixers, and discreet officials who can pass messages, arrange introductions, or provide limited criminal assistance. His most trusted contacts are connected to the society of Ouroboros.