Blade of Grass

Blade of Grass
Weapon (scimitar), legendary (requires attunement)

The razor-sharp grassy blade of this sword is able to slash with uncanny precision. You gain a +3 bonus to attack and damage rolls made with it. When you have advantage on an attack roll to hit with the sword, you can roll one additional d20 and choose which of the 3 dice to use. The sword can wrap itself around your wrist, becoming a grassy bracelet when you’re not wielding it, or return to your hand at will (no action required).

Sweeping Strike. As an action while wielding this sword, you can make a broad slash to hit multiple targets. Each creature in a 15-foot cone must make a DC 18 Dexterity saving throw, taking 4d6 slashing damage on a failed save, or half as much damage on a successful one.

Grass Arm. As a bonus action while the sword is being worn as a bracelet, you can cause it to grow and wreath your entire arm in a grassy mass up to the shoulder. The grass takes the shape of a brawny arm, rippling with vegetal vigor and thistly thorns. This grass arm grants you the following benefits:

• You have a +10 bonus to Strength checks that involve the grass arm.
• Unarmed strikes made with the grass arm have a +3 bonus to attack and damage rolls, and deal an extra 3d4 piercing damage to targets you hit with it.
• The hand of this arm can transform into a blade or back into a hand at will (no action required). This jagged blade functions as the Blade of Grass, however the sword’s reach is increased by 5 feet and it deals an extra 3d4 piercing damage to targets hit by it.
• You gain 10 temporary hit points at the start of each of your turns. If you take fire damage, this property doesn’t function for your next turn.

The grass arm lasts until you complete a short or long rest, or until you dismiss it as a bonus action. Once Grass Arm has been used, it can’t be used again for 2d10 days.

Curse. The Blade of Grass will always reappear wrapped around your wrist when you complete a long rest. Each time you use Grass Arm after the first, the grassy mass engulfs more and more of your body while the effect is active. The fifth time you use Grass Arm, make a DC 18 Wisdom saving throw. On a failed save, the grass entirely covers your body and takes control of your mind. You become a hostile chaotic evil NPC under the control of the GM. You retain your statistics with these alterations:

• You permanently benefit from the effects of Grass Arm, which now applies to all of your limbs. The temporary hit points bestowed by this effect is increased to 20 at the start of each of your turns.
• You are considered a Plant in addition to your normal creature type.
• Your Strength score becomes 24 and your AC can’t be less than 18, regardless of what kind of armor you’re wearing.
• Any creature within 5 feet of you that touches you or hits you with a melee attack takes 2d4 piercing damage.

If you are reduced to 0 hit points, the controlling effect ends and the sword reverts to its bracelet form. Each subsequent time you use Grass Arm, you must repeat the saving throw to resist being controlled again.