Thorn Soldier

Thorn soldiers are plant-like monstrosities that invaded Loth. They appeared following a strange darkness that covered the country, and spread out from the Meladon Forest.
Each is close to seven feet tall, covered in thorns and with at least a dozen limbs. They look like twisted, stunted trees with deep, green leaves and countless thorns. Some of its long, spindly limbs function as legs, others as arms. Unlike the thorns over much of its body, the ones on the end of the arm-like appendages are thin, almost needle-like, and can be fired at an enemy.
They are capable of tunneling if allowed enough time, and can throw thorns over a dozen feet. To stop them, you need to destroy their cores, which are buried deep in the mass of vines. Destroying these without magic is difficult. The creatures tend to come in swarms.
They have a vicious poison in all their attacks. This needs to be neutralized before the victims can be healed; somehow the poison feeds on healing spells, which makes healing someone before removing it invariably lethal.
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The thorn soldiers are extensions of trees native to the plane of Nocturne. They are controlled by dryads which are bonded to the king of thorns, a type of tree. Should the portal which connects the worlds be broken, that would also cut the link between the soldiers and their trees.