Wyllowblade is a very rare +1 longsword that was once used by the elven fighter Siegbert.
Requires Attunement.
When you hit with an Attack using this magic sword, the target takes an extra 1d6 necrotic damage. In addition, while you hold the sword, you have Resistance to necrotic damage.
Wyllowblade can hold 3 charges. It regains 1d4 charge at dawn.
When you hit a creature with this weapon, you can expand one charge and force the target to make a strength saving throw against a DC of 15. If it fails, vines from the wound appear and force the creature to be restrained. The target can use an action on it's turn to try and break free.
As a bonus action while yielding Wyllowblade, you can use one charge to transform the ground around you in a 15 foot radius to grow vines, transforming it into difficult terrain for all creatures except for yourself.