I know a lot of vampire count players who use blood nights or black knights and they screen their units really well. They take cheap units of dire wolves on their flanks or their front or both so you don't force them to charge, if you do not destroy these cheap units quickly they will augment their combat resolution by charing your flank and you still have to deal with the knights. An inexperienced VC player won't use a screen for his blood knights, so take advantage of that.
The screening unit would make a perfect target for the terradons' drop rocks. Just fly them over and wipe out the screening unit. In the case of Blood Knights, who have to charge, just land your terradons between the knights and the screening unit (nearer the screening unit). This will force the knights to charge the terradons, who will flee over the screening unit. The Knights will be stuck against the back of the screening unit, so you will know where they will be that turn. Just be sure you have something in place to charge the vulnerable flank.
Very good points Caneghem, I'd also like to point out in higher points battles you can expect to see a hammer and anvil stragety using blood knights. If you see the unit of blood knights with a BSB and the Drakenhof banner, watch out, this unit can regenerate! Salamanders would then come in handy, and use Caneghem's stragety to help destroy the screen. But flaming attacks will help.
Cupped hand of the Old ones with a Slann would hurt his mages by tossing them your miscasts. Slann is really the way to go, maybe EOtG as well.
After trying heavy magic lists; I was still having trouble. I decided I'd take a skink priest on an engine with a Diadem of power. My plan was to just save power die each turn to have 6 dispel die while only taking up 1 hero slot. The rest of my army is saurus/hero on cold one also two units of cold one cavalry, one w a hero. I feel like, with the heavier undead units, it's almost necesary to flank them to get some static combat res, which is why I chose 2 cold one units on my flanks.