Yig is listed as normal. He's got a doom counter of 8 whilst needing 10 signs to seal his scaly ass away. He's a good short game option, but so far he doesn't FEEL much easier than Astharoth. Other than that Yig's campaign is a good way to break in newcomers to Omens (if not Elder Signs as a whole). The four investigators that come with the cthulhu pack are also a welcome boon, and none of them are weak links (though Harrigan might be slightly too powerful as long as he has access to yellow glyphs).
The Cthulhu campaign itself throws in some genuinely evil things -entry events? Ouch. So far however, loving the extra content and looking forward to more expansions in the future!