Sickle of the Sphinx (Patreon)

Weapon (sickle), rare (requires attunement by a creature with an Intelligence score of 13 or higher)

The blade of this sickle is made of an azure crystal. Peering through the translucent blade conjures a flurry of existential questions to your mind. You gain a +1 bonus to any Intelligence check or Intelligence saving throw you make while attuned to the sickle. You're proficient with the sickle of the sphinx while you're attuned to it, and it deals an extra 1d4 psychic damage to any creature it hits.

While holding the sickle, you can use a bonus action to pose a mind-altering question (such as a riddle or philosophical prompt) to another creature within 30 feet of you that can hear you and understands at least one language. That creature must succeed on a DC 15 Intelligence saving throw or take 1d4 psychic damage. This psychic damage increases by 1d4 each time you use this property against the same creature on a consecutive turn, to a maximum of 3d4 psychic damage.

What am I?

I cleave, deeper than flesh, down to the mind.

I prise, widening cracks already prevalent in thoughtless souls.

I crush, shattering the pride of those who believe themselves astute.

One could say the answer is a riddle left unsolved, but the truth is more crassly literal.

I am the blade I wield.