Since the errata, it's hard to work out who the real Queen to use this pendant is.

Currently I think it might be Amanda Sharpe.

Using Enraptured behind Amanda Sharpe, you can try to keep your pendant topped up with charges and preventing it from removing itself from the game. Also, with Amanda's additional card draw (or rather card filtering) from her ability, she can see those Segments of Onyx faster than other investigators, without even trying.

TLDR: David Renfield and Well Connected are good level 0 card options

The Dunwich investigators just get more and more complicated to build decks for. As more cards come out, the possibilities for their 5 level 0 cards just keeps increasing. Two fun ones to consider are David Renfield and Well Connected.

Ashcan's ability lets you ready an asset once per turn. Now of course most of us see Duke as the 'real target' for that ability, but it does work for any asset. David Renfield is a very powerful way of piling up money, and even better when you can use him twice a turn to really fine-tune the amount of time before the doom threshold goes over.

Once you've amassed loads of money, you can now use well connected to easily be at +4 to any test, twice a round. Considering Duke gives an effective +2 skill, once you hit 15 resources, then well connected becomes a better option in a lot of cases. This doesn't mean Duke does nothing though, they're still useful for a 2 damage attack or a 'Move-stigate', and they still also give you that +2 skill.

There are many level 0 card options, here's a couple I tried together, enjoyed, and wanted to share :)

This card is a really fun Level 0 include for Ashcan. His ability lets him ready an asset, so you can use this card at level 0 twice per turn.

(Since they added the XP version of Well Connected this is less cool, but still makes for a fun deck)

TLDR: you have to choose something that changes the game state, if able

You cannot choose 'each investigator loses 2 resources' if no investigator has any resources. However, you can choose 'each investigator loses 2 resources' if one player has a single resource only. The game state changes by choosing that option, so it is valid.

From the rules reference:

Must

If an investigator is instructed that he or she "must" choose among multiple options, the investigator is compelled to choose an option that has the potential to change the game state.

In the absence of the word "must" while choosing among multiple options, any option may be chosen upon the resolution of the effect – even an option that does not change the game state.

Lily is the trickiest of the five edge of the earth investigators to build at level zero. Everyone else can hit a niche and change it, but it’s hard to be a mystic with a 4/2/4/3 or 3/2/5/3 statline.

Utility spells are worth considering. If you build your deck with the end in mind, there are a few purple cards at any top-tier guardian might like: Ward of protection, promise of power, drawn to the flame, and the portals. Word of radiance is great if there is someone going bless heavy. Scroll of secrets isn’t bad, but it means foregoing dragon pole or the ultimate hammer. And enchanted blades are given, a solid weapon that won’t cost you guardian slots.

For guardian, prepared for the worst, sledgehammer, and Grete are fun. There are very few wrong answers but you’re going to want to level up your weapons and prepared for the worst is the way you’re going to find them.

Happy hunting, and Lily gets better with more XP: the more weaknesses you have, the more likely you get a payday from “I’ve had worse.”