These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fair for Its Day: For a 1920's pulp series with stories set in Africa, it manages to be less malicious than most. The nasty stereotypes are there, yes, but they are not used exclusively. There are several black characters who are well-rounded and sympathetic, not least N'Longa.
The 2010 Film:
Complete Monster: Malachi is an Evil Sorcerer who becomes a Sorcerous Overlord in Solomon Kane. Considering himself the Devil's servant, Malachi ingratiated himself to Josiah Kane to bring Josiah's dead son Marcus back to life, but restored him as an undead abomination bound to Malachi's will to serve as his Dragon. Malachi took over the lands and has the innocent kidnapped for slavery, or simply murdered. Others he just turns into flesh eating abominations. Malachi later has the leaders of the resistance against him crucified and when Solomon Kane confronts him, Malachi tries to sacrifice the innocent Meredith to open the gates of hell and send Solomon to eternal torture-as well as the rest of the world.
The Untwist: It didn't take any audience very long to guess that The Dragon was Kane's older brother Marcus behind the mask.
What an Idiot: Sure, Josiah Kane, give your lands and wealth to an evil sorcerer in order to heal your badly injured eldest son. Because we all know Faustian pacts have a long history of NOT backfiring. Oh, I'm sure all those thousands of people on your lands won't suffer under his rule and even if they do, what's the suffering of hundreds next to one Jerkass son's health? What could go wrong?