I was also running
Harvester of Souls, and
Blood Artist like you. I had side boarded
Grim Haruspex and
Zulaport Cutthroat in case i needed to get more draw and more life. I had also decided to go with
Phyrexian Altar. I was running
Pitiless Plunderer along with the Altar for more ramp. I was also running
Crawlspace,
Fog Bank, and
Guard Gomazoa, as a defensive front to let me build my engine in peace. I was also running only the minimum 4 demons to fulfill the obligations of
Liliana's Contract.
Harvester of Souls, Razaketh,
Rune-Scarred Demon, and
Demon of Dark Schemes.
It was very similar in a lot of ways.
And ... uhhh ya ... FYI. You can run
Aminatou, the fateshifter in the 99 in this deck and if all goes to hell and you have horrible luck, you can -6 her in the late game and stick people with a crapload of apostles!
And she could also double as a tutor engine on her -1 targeting
Sidisi, Undead Vizier or
Rune-Scarred Demon.
I have only come up with two strategies that fully maximise both her abilities and neither of which are with her as the commander... There is the Apostle deck that I just explained above. And you could also use here in a Breya deck as part of an end game combo, where you go infinite mana, sacrifice all your artifacts to Breya deal a crapload of damage and then -6 Aminatou, to steal other people’s board.
She’s a great planeswalker in the 99. But I have yet to find any real significant solid strategy with her as commander.