Thornpiercer

This rose has a stem large enough to hold like the hilt of a weapon. You can focus on the rose as a bonus action to cause it to grow one of the following weapons from its center: a dagger, shortsword, rapier, or whip. If the hilt already has a weapon growing from its center, the existing weapon withers away and disintegrates, allowing the new one to take its place.

You gain a +2 bonus to attack and damage rolls made with this magic weapon. In addition, targets hit by the weapon take an extra 1d4 piercing damage. If you are a druid or are proficient with either simple or martial weapons, you are proficient with the weapons that thornpiercer grows.

Each weapon option has a unique property:

Dagger. When you throw this weapon, only the blade is thrown from the rose hilt. Hit or miss, when the blade reaches its target, it erupts into a burst of thorns. The target and up to 3 other creatures of your choice within 10 feet of it must succeed on a DC 17 Dexterity saving throw or take 1d4 + 2 piercing damage.

Rapier. When you roll a 20 on an attack roll with this weapon, the blade’s thorns eviscerate the inside of the target and deal an extra 3d4 piercing damage. If the target was a Large or smaller creature, it must also make a DC 17 Constitution saving throw. On a failure, its hit point maximum is reduced by the amount of damage dealt by the attack. On a success, it’s reduced by half the amount instead. Once the creature completes a short or long rest, its hit point maximum is restored.

Shortsword. The first creature hit by this weapon on each of your turns must make a DC 17 Constitution saving throw. On a failed save, a creature takes an extra 1d6 poison damage and is poisoned until the end of its next turn.

Whip. When you hit a Medium or smaller target with this weapon, you can attempt to grapple it with the whip. When you do, the target must succeed on a DC 17 Strength saving throw or be grappled by viny whip. A grappled target takes 1d4 piercing damage from the whip’s thorns at the start of each of its turns until it’s freed. A creature can use its action to make a DC 17 Strength check, freeing itself or another creature within its reach on a success. The whip breaks off from the hilt when you successfully grapple a target in this way, allowing you to move freely while the target remains grappled.