Best thing to do is just run past any npc's you encounter, which isn't too many but they are strong (Greater demons being your main threat). Once you reach the tree spirit, the safest thing to do is find one of the safespots wherte you can mage/range the Tree Spirit without it being able to touch you. There is a couple, and I'm sure there is a picture in the quest guide on the Tip.it website of one of the safe spots. It's vulnerable to magic too, so it isn't too hard to kill. Good luck! ~Ivaked