Yay! I managed to win level 4 difficulty without Tuskal and with a bizarre team. I struggle way more than with Tuskal, of course, but I feel it was a good strategy. I started with Mabek and Gheist and the Spooky ability helped a lot. I found Krogg later and used it as a shield and sacrifice for Mabek.
In the beginning I was planning on using Gheist as a sacrifice, since it's almost designed to die with its last ability (which I did not take), but Krogg's ability gets better if it misses health, so I wanted it to be the shield and take damage for the team. It worked well.
I always manage to find Circlet of Acuity, in some way or another. It's the legendary item I find most of the time. I dropped it on Gheist to curse a lot (in more than one way XD). It worked well against the spiky dragon final boss.
I love Spooky team. It's very fun to not care about monsters dying, or at least care a little bit less, thanks to the POWER OF SPOOKY NECROMANCY >:)
I'll count this as my actual first 4 lv win, since the last one I "cheated" with Tuskal