I owe this handbook a big thank you for helping me win a Junkyard Wars competition (entry here for anyone interested). Thank you for your handbook on Truenamers, Zaq.

One feat that I think worth a brief discussion is "Mark of Avernus". The costs are steep (a prereq feat, being LE and a Devil) but if you can swing all that, you get the ability to use a spell-like ability as an immediate action once per encounter. Seems to work well with the many debuff and crowd control abilities that Truenamers get, but I'd be interested to see what other people make of it.