The Duke D'Omas was a Spark even his followers considered excessively insane. He appears to have been wealthy, however, which can buy a lot of forgiveness. Baron Klaus Wulfenbach blew up the Duke's mountain prior to the start of the main narrative.
The set of brothers that crewed the walking gunboat Vienna 707 were less fortunate, being scattered with the destruction of their machine; Moloch and Omar eventually made their way to Beetleburg and even more bad luck. The fates of the others are uncertain, although it appears that at least some of them had escaped. This may be important in the Future.
D'Omas' eccentricities ranged from the Spark-typical to the downright peculiar (building paramours, whether clank or construct, to match his "unique" taste in women). Despite his madness, D'Omas must have been a competent enough Spark for the Baron Wulfenbach to remember his style.