Hmmmm, the main issue with making a Lich is people are going to wonder why such a powerful and generally evil character would be in a guild. Considering what needs to be done to become a Lich, it's not exactly easy for a good-aligned character to do. Now that's not to say a Lich couldn't later come to regret their choices and feel shame/guilt over the people they killed and everything else they did to achieve Lichdom, but for the most part those sorts of characters are going to be better suited to more evil/shady guilds.

There's also the fact that Liches are extremely powerful, not only in terms of combat, but also because they're essentially immortal. Because of their strengths, a lot of GMs might be very wary of accepting one as a player's character, simply because of the huge potential for godmoding with one.

What might help you in your search is using the new guild finder and looking for guilds that mention having darker themes or allowing for criminals in the little blurb thing you see for each guild. This may not do much good if your character is good or neutral, but they'd have a better chance getting into a darker guild simply by principle.

While I was lookin through the guild listings yesterday I saw a couple of guilds listed as having darker themes. One that would probably fit you the best is called the Crimson Razor. They have an Enjin page and stuff, but you should be able to find them fairly easily with the Guild Finder in-game.