Tsabo Tavoc was my first commander too! So many good memories with her. To help with the high mana cost Revel in Riches could be fun and also offer an alternate win con. In addition Thornbite Staff wrecks with assassins. Avatar of Woe is a beast of an assassin too.

Another creature that makes everyone hate you more (also isn't a bad commander) is Kaervek the Merciless.

But alas, commander deck finessing is a slippery slope that never ends.

@RyProv, Thanks for the suggestions! I think I might go with Thornbite Staff and especially Avatar of Woe. Kaervek the Merciless is mean, no doubt, but I'll probably leave him and Revel in Riches out for now, because they don't really fit the theme as much. But if mana ramp seems to be an issue, I might reconsider Revel. And yes, deck finessing definitely is a slippery slope!