I believe that "bal" is a negative prefix in hebrew (I may be incorrect)
On the other hand that would make sense considering that these are literally "fallen Seraphim" according to In Nomine, a roleplaying game from Steve Jackson Games.
The Balseraphs are the highest of the low. The highest ranking demons in Hell, they're cursed with the ability to make anyone believe anything that they themselves believe
Other demons available : Balseraphs, Djinn, Calabim, Habbalah, Shedim, Impudites, Lilim