Personal Truename Backlash
( Tome of Magic, p. 229)[General]
Your personal truename is so charged with magic power that those who fail to speak it properly are warped by reality run amok.
Prerequisite
Obscure Personal Truename (TM) , 15 Hit Dice,
Benefit
Whenever a creature fails by 5 points or more in an attempt to speak your personal truename, it immediately takes ld6 points of damage for every Hit Die you have.
Normal
The consequence for failing a Truespeak check to say someone's personal truename is that the utterance, truename spell, or other ability fails as well.