Advice for a noob

[Jack-Hammer]

First choice after the the battle box? I would suggest skarlok, a great model for any caster, and either the book or cards. The book gives you more of the background but the cards give you all the model rule, which will allow you to proxy different models before you buy.

Then to get to 25pts I'd suggest a unit. Most people will probably suggest bane thralls, they are the easiest to use, but any of their units are great. A lot of the strength in Cryx is found in their units & solos

[cody]

The card pack doesn't include models released for Mk II and later, the book has everything (aside from models introduced in Wrath of course).

[Vinsklortho]

If Cryx is similar to Ret in this manner then find a really good "module" that people rave about on the internet and then fill the rest of the list with whatever fun stuff sounds interesting to you. By module I mean a combination of caster, unit, solo, and/or jack that have great synergy together and can function regardless of the other parts of the army. For instance in Retribution I run Ravyn, MHSF+UA, and Discordia together. The rest of the army could be made up of whatever I think is cool or fun and it will still work as my primary strategy is in place. With Cryx I imagine including a solid base of Bane Thralls+UA with Bane Lord Tartarus gives a good base to allow you to be creative with the rest of your army.