[X] Research a method to empower our friends using the Fire Within to enhance their survivability. Most distressing indeed to find our friends severely injured during the fight. Start with a Shield Coating that burns Evil Vines that try grasping on them, perhaps? Would require some form of Tree Stuff to anchor the spell, so imbuing a shaped piece of branch, leaf, bark, or nut with some Fire Within to make it "alive", and anchoring it with the Intent to Protect the bearer, but specify who or what gets to be Protected? Hmm.
[X] Telekinesis, second try: Maybe movement magic is a better place to start? Try to assert the magic energies that move roots, to tear hostile vines off trees.
[X] Write-in: Study the Vine's attacks. What was it they were looking for with that first attack? Is there a weakpoint in the attack method we can use to reduce the damage done? Can we guide the attacks so they seemingly find their target whilst also not doing any damage to us? In short, what can we learn so that future attacks do less damage and give whoever is creating these Malice-Entities as little information about us as possible.
[X][Minor Question] Speak to Mr. Tavish about the existence of the Fire Within and our ability to shape it, and ask him if there exists other sorts of "stuff" Within, such as the Light Within.