So the Tantalus has made it into my primary list now.
With the FAQ forcing my army to go ynnari I had to drop my mandrakes and had a few choices to replace them. Solitaire, striking scorpions OR turn my 3 venom (carrying incubi and my characters) into a tantalus.
The fire power is phenomenal and to offset the eggs in one basket problem I'm moving the incubi into the raiders (with wyches) and the 2 warrior squads from those raiders into the Tantalus.
This makes my list 6 drops so a good chance of going first.
For Khaela Mensha Khaine!