Yes I noticed that Mordies worked nice vs the Wraith when I did Improved Irenicus with a party, didn't really harm him much, but they were excellent tanks. Those aren't really an option for a solo Inquisitor
The Wraith has less than -20 AC?! Yikes, would need a Kensai to hit him regularly! My PC archer in the aforementioned group had -23 THAC0, but for a fighter to attain that kind of accuracy.... The one thing that really puts you at a severe disadvantage when trying to actually tank the Wraith yourself though, is his bloody strength drain. After just a few hits he will totally have crippled your damage and THAC0, imagining going from 25 to 9 in a matter of a few rounds