Mythos Bustin' Diana

First things first: This deck runs no arcane-slot spells (to start). Mystics are inherently inconsistent due to their need to draw spells and Diana is doubly so because of her fluctuating willpower. The baseline spells (Shrivelling, Rite of Seeking, Mists of R'lyeh) don't boost your willpower at all. In order for something like Shrivelling or Rite to be better than Machete or Flashlight, you need to have 4-5 willpower, meaning you have to have played 3-4 cancels. This might happen by turn 4 or 5, but you need to be able to do stuff before then. Because of this, I'm avoiding the standard spells until I can buy upgraded versions that boost willpower.

This deck's concept is to neuter the mythos deck as much as possible and allow your teammates to get everything else done. "Let me handle this!", Deny Existence, Ward of Protection all take the sting out of the mythos deck. Dodge, Hypnotic Gaze, and Deny Existence all prevent the monsters from being too much of a problem. By using these damage cancelers, Diana can drag monsters around to set up some really nice uses of Storm of Spirits and can also tank many monsters using Guard Dog and Survival Knife to punish them. David Renfield bankrolls this whole endeavor and is happy to take a beating from a baddie when you need to avoid the doom (allowing you to follow up with Survival Knife).

Dark Prophecy is included mostly as a deck thinner. On standard, as long as you're 2 up on the skill test, you can safely use Dark Prophecy for essentially no cost, gaining back the resource and the card all while buffing up your willpower.

Beyond the inconsistency of your willpower for spells like Shrivelling, I leaned into using weapons because I wanted to include Prepared for the Worst to tutor out the signature Twilight Blade. Twilight Blade is essential to your strategy, allowing you to get massive value out of all the cancels you run. Having Machete and Survival Knife allows you to use the tutor without fear of whiffing.

Many people are shy to use Delve Too Deep, but with Diana, you shouldn't worry too much. She has plenty of cancels to deal with the worst of it and greatly benefits from the injection of experience.

Speaking of: Below is my planned progression of experience.

First Priorities: Machete into Timeworn Brand. While expensive, the Brand adds a necessary boost to your strength to improve fighting consistency and allows you to "nuke" one enemy a game.

Guard Dog into Beat Cop. Again, this boosts your strength and allows you to easily "ping" odd health enemies.

Next Priorities: Ward of Protection into Ward of Protection. I'd avoid level 5 Ward, but level 2 allows you to more easily cancel the nasty Mythos cards.

Flashlight into Rite of Seeking. I'm planning on stopping at Rite (2). The willpower boost is welcome and can make you into a valuable contributor to the clue game. However, it is expensive and secondary to your primary role.

Survival Knife into Shrivelling. This is more of a late campaign buy in order to have more firepower when facing scarier late campaign monsters. The combo of Timeworn + Shrivelling is nice because you don't HAVE to use Shrivelling and can save it for when you really need it, reducing the risk of bad stuff tokens taking you out prematurely.

Other Cards to Consider: Vicious Blow into Vicious Blow

Dark Prophecy into Counterspell

Delve Too Deep into Emergency Cache. By the time you buy some of your XP cards, Renfield may not be able to keep up with your needs, so the Cache becomes necessary.

Further Thoughts: Police Badge and Crystalline Elder Sign could be good to take up your accessory slot. Brother Xavier would fit nicely, but is expensive and you'd probably want to get Charisma. Well Prepared combos nicely with Twilight Blade, but may not be consistent enough if you don't also buy Physical Training. Seal of the Elder Sign lets you further reuse your cancels!

If I were to run any of these, "Let me handle this!" and Intrepid would likely be on the chopping block.

Let me know what you think! Thanks for reading.