Luminessence

Substance, common

This liquid is identical to a flask of holy water, but possesses additional properties.

• If shaken, it emits bright green light for 20 feet and dim light for 20 feet further for ten minutes. The water retains its potency so long as it’s sealed and can be reactivated by shaking.
• If applied to an object or creature, they remain lit for ten minutes and cannot become invisible.
• Any message written with the substance will be invisible to the naked eye, but glow when exposed to a Light spell.
• When used to attack, the target takes additional damage equal to the user’s Intelligence modifier (minimum 0).