This rose has a stem large enough to hold like the hilt of a weapon. You can concentrate on the rose using an 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 the center, the existing weapon withers away and disintegrates. This weapon has 2 transformations per day, with any transformations exceeding this count will be causing the wielder to take 1d4 of your health, charge recharge at dawn. However the first form the rose takes after a short rest does not expend a charge.

You gain a +2 bonus to attack and damage rolls made with this magic weapon. in addition, targets hit by this weapon take an extra 1d4 piercing damage. If you are a druid or are proficient with simple or martial weapons you are considered proficient with the weapons that grow from Thorn Piercer while attuned to it.

Each weapon option has a unique property with the save DC of 16:

Dagger: Upon attack deal 3d4 piercing damage on target, however, f the weapon is thrown the blade will detach from the rose hilt. whether the blade hits or misses, whenever it reaches its target it will erupt into a burst of thorns. The target and up to 3 other creatures of your choice within 10 feet of the blast must succeed on a Dexterity saving throw or take 1d4+2 piercing damage. You can use a bonus action to cause the blade to regrow within the hilt, this does not exhaust a charge upon the weapon as you are not changing the weapon type. 

Rapier: Upon attack deal 3d8 piercing damage on target, however, when the wielder rolls a 20 on an attack roll with this weapon, the blade's thorns eviscerate the inside of the target of the attack and deal an extra 3d4 piercing damage. If the target was a Large or smaller creature, it must take a constitution saving throw. On a failure, its hit point maximum is reduced by the amount of damage dealt by the attack. On success, it's reduced by half the amount instead. Once the creature is short or long rested its maximum hit points are restored.

Shortsword: Upon attack deal 3d6 piercing damage on target, however, the first time you hit with an attack on your turn, the target of that attack must succeed on a Constitution saving throw or take an extra 1d6 poison damage and be poisoned until the end of its next turn.

Whip: Upon attack deal 3d4 slashing damage on target, however, when you hit an attack with this weapon, you can choose to attempt to grapple the target if it's no more than one size larger than you. When you do, it must succeed on a Strength saving throw or become grappled by the thorned whip. While grappled, the target takes an extra 1d4 piercing damage at the start of each of its turns. The target or another creature can use their action to reattempt the saving throw, releasing them upon success. The whip snaps off from the hilt when you successfully grapple a creature with it, allowing you to move freely while the target is grappled. You can use a bonus action to cause the hilt to regrow the whip, this does not exhaust a charge upon the weapon as you are not changing the weapon type. 

Upon attuning this weapon you are granted with a new form that the Thorn Piercer can possess. The Thorn Piercer can now grow that of a scythe from its center dealing 3d8 worth of damage, additionally when swung this weapon will release a cloud of poisonous spores that deal 1d4 poison damage in a 5 foot radius of the impact of the weapon to anybody standing within it. On a nat 20 attack roll that hits this weapon deal an additional 2d4 poison damage.

Proficiency with a Dagger allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: After attunement to this weapon, every 2 levels the wielder can sacrifice 1 long rest in order to add an additional dice roll to this weapons damage rolls., druid who has sacrificed 4 short rests instead to master the arts of each of the weapons form, upon the fourth rest you gain mastery of not only the fourth weapon type but it's hidden form as well, Finesse, Light, Thrown, Nick