Chaosmancer
Legend
@Chaosmancer Well, I'd prefer the conversation not to get off track from what I started this thread to discuss. I'm going to request that you if want to discuss the merits of familiar types, that you please start your own thread and pick it up there.
EDIT: Sorry, I had to help my girlfriend unload some things and my posting was interrupted. I think your basic question has merit: "Why would a spellcaster take on a fiendish familiar, knowing it was evil?"
However, I think that question applies universally across D&D and is not particularly more relevant to the discussion of the hezrou-as-black-magic-familiar than it is to many other parts of D&D. It's a question I think mandates a wider audience and more inquiry than I can accommodate.
By comparison, it would be like having a conversation about redesigning the rust monster, and then getting sidetracked in a debate about which weapons/armor components would be made of metal. Sure, it's tangentially relevant. However, the debate about metal weapons/armor applies to far more situations than just rust monsters – heat metal, whether it can be used to block certain divination spells like detect evil and good, magnetism & lodestones, druid prohibitions, certain oozes which either do or do not corrode metals, world-building and technology levels, etc.
A good point, I'm pretty bad about getting focused on an aspect or detail of a discussion and following that far off the beaten path.