Devotion to Duty is a great solo adventure for new warriors.
It has a great story line where you are an initiate to a fantasy deitys order. It makes for a nice change from the usual 'dungeon delve' whereby you are exploring a dungeon/tomb/cave for treasure. Not that theres anything wrong with those but this one lets you feel like you are participating in the narrative of a fantasy adventure.
Plenty of replayability and lots of fun to be had.