Initial thoughts:
*Given Birdsie's clarifications on Discord (Eldritch isn't dangerous to Sol, Transgression can be channeled into minimally harmful paths), I'm alright with either Eldritch or Transgression. Eldritch best fits our initial goal of a near-fully stacking Aspect that can push us to a 4x Aspect stacking efficiency - something that will save us tens of thousands of XP in the long run - but Transgression as a solution for Will isn't bad either. We can basically become Kazuma - proactive, highly competent but lecherous - which is a huge upgrade in terms of actual play experience compared to being highly competent but crippled by Will requirements.
*Vision seems promising initially, but has two severe flaws. 1) It doesn't do anything against mindless undead, golems, natural disasters, enemies with strong mental defenses... it's an incredibly narrow Aspect that's not really worth spending XP to level more than once or twice. Inflicting madness on others is just an extremely unwieldy and morally questionable method of achieving things. 2) Sol experiences despair at all the things he sees but can't change; if he's empowered to see the dark side of life super-well, it's entirely possible his despair will flare up and become even worse. But really 1) is my main concern; I cannot emphasize enough how huge a mechanical mistake it would be to give up a highly-stacking or actually useful Aspect for something this narrow and bad. It is literally like taking thousands of Will (dozens of individualized classwork actions) and throwing it in the garbage.
*The Revolver seems excellent. The Lantern and Athame will both probably be useful in this upcoming fight. Given these considerations, have two build plans:
[X] Plan Carnage
-[X] Aspect: Eldritch
-[X] Red Athame
-[X] The Revolver
-Take Eldritch, Revolver and Athame. Arm Penelope with the Athame for this adventure; Justice will have a better grasp of when it's worthwhile to mete out incomprehensible agony than we will. She'll likely only use it on truly irredeemable creatures or when absolutely necessary, which is right and proper. Her ability to normalize the capabilities of combatants in a fight means she benefits incredibly from a save-or-lose on-hit effect like the Athame, and her peak human fighting skills make her well able to wield it.
-Offer her a loan of the Revolver too, if Sol deems it necessary and prudent.
-This also has the benefit of playing into Sol's King of Magi role as (overpowered) mentor and support; Penelope is the one with the sword and we're the heavy artillery and finder of secrets that arms and advises her.
-If we can spend XP, either have a separate vote for that or hash it out in the Discord. We've got plenty of ideas on how to use our XP before the adventure if it's permitted.
[X] Aspect: Eldritch
[X] Red Athame
[X] The Revolver
[X] Plan Scumzuma
-[X] Aspect: Transgression
-[X] The Spirit Lantern
-[X] The Revolver
-Take Transgression, Lantern and Revolver. The Lantern neutralizes spirit-based enemies weaker than it and introduces a clock for stronger enemies. The Revolver is a solid panic button. Transgression turbocharges our scaling long-term as we get much more effective Will. By taking two immediately useful Artifacts we somewhat make up for Transgression's lack of immediate power. This build will really change how Solomon plays as we'll be less concerned with juggling Will and instead have to consider how to appease his Transgression niche, but we'll be able to actually do more things.
-If we can spend XP, either have a separate vote for that or hash it out in the Discord. We've got plenty of ideas on how to use our XP before the adventure if it's permitted.
[X] Aspect: Transgression
[X] The Spirit Lantern
[X] The Revolver
[ ] Plan Cradle
-Take Transgression, Cradle and Revolver. This plan hopes that Revolver provides sufficient safety for us to get away with taking Cradle, and Transgression ensures we actually have the Will to exploit it - else Cradle is basically a wasted option since it's all potential and will require months of work to unlock. We'll also need a serious Will reserve to defend ourselves from the attention Cradle draws.