There is one very easy way to kill the Tree Spirit on Entranta for the Lost City quest: magic. Get at least 29 magic and take runes and robes to cast Earth Bolt around forty times and a teleport spell. This helps getting out without ending up in level 29 wildly. Without using runes, go into the tunnels and kill zombies until you get an axe. Cut the tree and get attacked. Run around, and without it following you, hide behind the giant mushrooms to the left of the tree. Set your combat to spell and Earth Blast and kill it within 5 minutes. Cut the tree and teleport out.