Monterey Jack (Relics of the Past) - This Belongs in my Hand

You will be functioning mainly as a cluever. Use your high to evade or Backstab enemies, while gathering clues. You will want to keep getting clues off of locations so that you can make use of your ability to cheat out relics and charms. "I'll take that!" gives us action compression and and a discount on playing our items from hand when we do the two things we're best at: evading and investigating. Since we have 7 accessories, we will use In the Thick of It to have Relic Hunter at level 0. Hallowed Mirror lets us heal, while Talisman of Protection saves us from dying. Dowsing Rod, St. Hubert's Key, and Mouse Mask bump up our already decent investigation skills.

Upgrades:

The first upgrade I would take is Underworld Market. It lets us build a side deck of useful cards while keeping our main deck full of relics. Cards to put into the market include Lockpicks, Burglary, Hidden Pocket, Disguise, Tennessee Sour Mash, and Pickpocketing, British Bull Dog. Upgrading our Pickpocketing makes it fast and gives us resources, so if you are doing a lot of evading, I would suggest upgrading it.

This deck is also pretty good at getting resources. Our elder sign gives us a bunch, Cheat the System is a fast 3-5 resources, "I'll take that!" gives us a discount, and The Red Clock gives us resources. I often found myself with more resources than I knew what to do with. Lola Santiago gives us two stats we love, and lets us spend resources for fast testless clues, but you might want Charisma so you can have both Lola and Dr. Elli Horowitz out. Streetwise is another great resource outlet.

Obviously you want to upgrade your relics, since the main point of this deck is cheating out a bunch of relics. There are plenty of options, so it depends on what campaign you are playing and how many people you are playing with. For solo, you want cards that give you more action compression/versatility, so The Red Clock, Eon Chart, Segment of Onyx, Ancient Stone are great choices. Cards like The Skeleton Key, The Chthonian Stone, Grotesque Statue, Hemispheric Map, Lucky Cigarette Case, or Otherworldly Compass are possible options depending on what you are looking for. The order of what to upgrade is up to you, as this deck is very flexible and adaptable.

If you are playing multiplayer, "You handle this one!" might be a good choice to help protect against your 1. Deduction is also a card that is better in multiplayer, as it is pretty useless on 1 clue locations.

When taking cards out for upgrades, most of them will be pretty obvious (Faustian Bargain for Cheat the System), and you probably want to take out some of the weaker level 1 relics in place of the better ones you will add, as you only have so many slots. Again, this is up to you as you play this deck and get a feel of what is and is not working.