Flame Tongue Flail 2024
Weapon, rare, (requires attunement)
While holding this magic weapon, you can take a Bonus Action and use a command word to cause flames to engulf the damage-dealing part of the weapon. These flames shed Bright Light in a 40 foot radius and Dim Light for an additional 40 feet. While the weapon is ablaze, it deals an extra 2d6 Fire damage on a hit. The flames last until you take a Bonus Action to issue the command again or until you drop, stow, or sheathe the weapon.
Properties
SapMastery
If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.
Source: System Reference Document 5.2 (Wizards of the Coast) · License: Creative Commons Attribution 4.0 details