Cruel Motivation

Weapon, very rare (requires attunement)

This well-crafted whip is made of braided black leather and lined in tiny barbs that resemble a ram’s horns, each meticulously forged in detail. It is wreathed in smoke and festooned with heavy iron tips.

You gain a +2 bonus to attack and damage rolls made with this magic weapon, which has a reach of 15 feet. When you hit with an attack using this magic whip, the target takes an extra 2d8 necrotic damage.

In addition, those damaged by this weapon must succeed a DC 15 Wisdom saving throw or gain a temporary madness effect.

Curse. This whip is cursed. Becoming attuned to it extends the curse to you. As long as you remain cursed, you are unwilling to part with the whip, keeping it on your person at all times. While attuned to this weapon, you suffer from grievous nightmares, and your mind wanders toward dark deeds while awake. Once per week, at the end of the week before you sleep, you must succeed a DC 15 Wisdom saving throw or awake the next day in a blind rage, attacking anything nearby for 1 minute.

You can break the curse in the usual ways. The whip then becomes a +2 whip with no other properties.