I'm going to be a bit candid here so please don't take this personally or the wrong way. Most evil guilds lack creativity. Their main premise tends to be something like this:
Let's be a mischievous group that collects information and wealth. Also people can hire us to do evil deeds if they want to.
or
Let's just get a group of evil people together and see what happens.
Evil needs an
objective. It needs tangible goals, plots, schemes, missions, and end game success. Good doesn't have this problem - they have it naturally:
Let's stop evil.
To be truly successful as an evil faction you need a vision for where you want to end up and progressive steps of how to get there. As I'm clearly biased I won't use my own guild as an example - I'll give you another:
Evil Deity related factions. These have astute objectives provided by their Deity and PCs who worship that deity are determined to carry them out. Just look at the most successful evil factions as of late:
- The Temple of Auril
- Zhentarim (Bane)
- The Church of Shar more recently.
Do you notice something in common? There is a greater purpose at work for all the scheming and plotting.
If you need an example of something non deity related look no further than The Cult of the Dragon (although one could make the argument that Dracoliches are the deity).
The goal of COTD is to bring about the apocalypse and have undead dragons rule the world. That's an end game and a vision everyone who joins knows and is working towards. It's not just "let's just sit around and be evil and see what happens."
TLDR: Evil needs a tangible objective.