Harmless Offering is key here. Demonic pact about to run out? Give it to them! Midnight Oil run dry? Here ya go! Want to slow them down with some damage to their board? Pass over that liches mastery and crack a gonti's (and with sanguine bond out you get twice the value!)
Additionally, the big speed machine for this deck is getting a fire of invention and literally any two-piece combo. Additional bits can be placed in sideboard to be snagged for free as a nice GOTCHA moment.
Elderspell is pretty much there because of value. Getting a Lilliana to actually ultimate with this setup is basically game set and match. Harmless offering fires of invention at that point if possible and just play out your hand.
Harsh Mentor can basically be replaced with any nice low drop that punishes the enemy. It's meant to draw the fire off of you and give you something to block with. Epicure of blood and Sanguine Bond make for a nice instant if you can get it to go off that turn.
That's basically the deck. Ideal hand would be four lands a fires of invention harmless offering and demonic pact with a draw into Abrade on first turn.
As a note, Lilliana and Elderspell can be replaced with basically anything. I personally ran out of ideas of what to put in those slots and figured can't go wrong with a land fetch and mana ramp. Liliana herself is also a bulk of the price, cutting that out EASILY turns this into a nice budget deck.
