This palm-sized whetstone is carved from black basalt veined with silver and warm to the touch despite its stone body. Its narrow faces are etched with hundreds of tiny tally marks, each one ending in a different symbol: a blade, a quill, a tongue, or a closed eye. When drawn across steel, it sheds sparks shaped like punctuation marks. When drawn across parchment, it leaves no abrasion, but the words briefly glint with a cold blue light. New tallies appear with the faint sound of a knife being honed.
Edge of Reason
As an action, you can draw the whetstone across one weapon, tool, or piece of writing for 1 minute. The item becomes magically sharpened until your next dawn. A sharpened weapon gains a +1 bonus to attack and damage rolls and deals an extra 1d6 psychic damage on the first hit it makes on each of your turns. A sharpened tool grants you advantage on one ability check made with it, after which the magic ends. A sharpened piece of writing grants advantage on the next Charisma (Persuasion), Charisma (Deception), or Charisma (Intimidation) check made using its words, after which the magic ends.
The Count Remembers
Whenever you use the whetstone to sharpen a weapon, tool, or piece of writing, one tally appears on its surface in a language you understand. The whetstone records the item's name, the date and place of sharpening, and the name of the creature that used it, if known. It can hold an unlimited number of tallies, which remain legible only to you and creatures attuned to the whetstone.
Reckoning of Claims
The whetstone can distinguish truth from rhetoric. As an action, you can touch it to a written argument, oath, contract, or spoken statement lasting at least 1 minute. You learn whether the statement contains a deliberate falsehood made by its author or speaker, though you do not learn which part is false. You can use this property three times, regaining all expended uses at dawn.
A Sharper Retort
When a creature you can see within 60 feet makes a Charisma check or a saving throw against being charmed or frightened, you can use your reaction to sharpen one remembered argument. The creature must roll a d10 and subtract the result from its check or saving throw. You can use this property after the roll but before the outcome is determined. Once you use this property, you cannot do so again until dawn.
Cutting Words Made Manifest
Once per dawn, you can use an action to speak a perfectly honed rebuttal at one creature within 60 feet that can hear you. The target must succeed on a DC 19 Wisdom saving throw or take 8d10 psychic damage and become stunned until the end of your next turn. On a successful save, it takes half as much damage and is not stunned. A creature that succeeds on this saving throw is immune to this property for 24 hours.
The Final Tally
The whetstone keeps a separate count of every time one of its properties is used. At 100 total uses, it reveals a hidden inscription naming the greatest unresolved argument in the world, chosen by the DM. Until that argument is settled, the whetstone's Cutting Words Made Manifest property deals an additional 2d10 psychic damage, and its bearer has disadvantage on Charisma checks made to knowingly speak a falsehood.
Lore
The Last Word Whetstone was made for a philosopher-king who believed every war began with an unsharpened argument. His court employed duelists, barristers, scribes, and spies, all competing to add their work to the stone's ever-growing record. Legends claim that the whetstone has never forgotten a promise, insult, betrayal, or victory, and that one day its tally will become complete enough to judge the world.
History
The stone was created by the artificer-priest Veyra Quillhand, who ground a fallen star into its silver veins and quenched it in ink taken from a demon's contract. It passed through the hands of a famous duelist, three rival kings, and an order of impartial judges. During the Treaty of Seven Bells, every signer used it to sharpen the treaty's quills; the agreement lasted exactly one generation before the stone's tally revealed that one signature had been forged. It was last seen in the ruins of the royal debating hall, where its records are said to include the true names of countless historical liars.
