Dont forget about unlocking the Master Haemi. Almost no point in taking a regular dude over the Master.
If you are building a Coven heavy list (ie DT Liquifiers or PoF Wrack Carpet), the Twisted Animator WLT to resurect D3 dudes is AMAZING. Dont forget, this happens during the Command Phase. Primary points are scored at the END of the Command Phase. ie, you can ressurect dudes ONTO the point, and re-take it!!!
Haemoxytes are probably my fav unit in the new codex. SO durable for their cost, and 10 with 3 DT Liquifiers are NASTY.
If you are in a Deathguard Heavy meta, the Poisoners Ampule will stop that pesky Fight Last Aura that everyone is taking these days.
Lastly, this is probably the best Character to preform Mission Specific secondaries. He doesnt want to shoot, so its not a waste. And he is nearly impossible to kill, so good luck stopping him.
Now if only they hadent taken away all his cool Combat Weapons. Seriously, his attacks are a mess...