FYI
Grinding the reaver for a +3 tome is NOT the best way to get a +3 tome...
Do the Shroud instead... At your 20th, you see 6 tomes, and there's a decent chance that several will be +3... One of my characters got offered 4 +3 tomes and I had to choose...
However, one got zero +3 tomes, so that's possible too... BUT he got his pick of +2 tomes... AND running the Shroud gets you ingrediants, while running the Reaver gets you nothing (maybe a little cash, although selling ingrediants makes you a LOT more cash if that is what you're after)