TL;DR: Interesting update for sure! A must-have for a Spell heavy and orientated Mystics. It brings more value to Wither + Shrivelling combo / Sixth Sense + Rite of Seeking combo / Attack + Investigate + Evade Spells builds.
When level 0 of Sign Magick was often clunky and had a hard time finding a real value in decks, it was with Familiar Spirit the only way to open up your Arcane slot. The question was then: should I sacrifice an Ally slot, or a Hand slot?
And now, we have this upgrade and the The Hierophant • V in the same box that both offer an extra Arcane slot.
Let's look closer at these 2 cards:
• Free AND Fast when in your starting hand. It will most likely not be your first mulligan target as you will focus on your key spells.
• 3 resources, 1 card and 1 action to play - 6 actions. As with every other 'extra slot card', it becomes less and less relevant the later you draw it, knowing that you will need 1 action to play this card AND 1 action to play the extra Spell/Accessory. This makes this card useless in the late game when actions become really scarce.
• Doesn't bring any icons for skill test unless you bought Moon Pendant as your extra Accessory.
• Brings flexibility between your Accessory slot and your Arcane slot. Bring 3 Arcane spells and 2 Necklaces and play down the first 4 cards that come to your hand.
• Takes the slot of Four of Cups that is a commonly used Tarot card.
• 3 resources AND Fast. Even in the late game, if you have your other spell in hand, it is worth playing it if you have extra resources as long as you have 1 action to play your spell. Uncage the Soul can also make it free!
• Brings one extra action PER TURN (2 when you have the 2 cards down), on one of your spells (!!!)
•• Use Sixth Sense with Jacqueline Fine and bring an Icon token. You are now investigating at a different location and find 1 clue. Use Sign Magick's to trigger Rite of Seeking to grab a nice amount of 4 clues at a different location [The rules of "As if" say: "Other card abilities or game effects resolved during the duration of the indicated ability or action are also resolved with the altered game state in mind."]
•• Use Mists of R'lyeh for evasion + move and send an immediate investigation on that new location with Rite of Seeking for an evasion, one move and 2 clues in one turn to make Ursula Downs feel like a sloth.
•• Finally a fun one: Borrowed Time will gain 1 free click per turn as it is a Ritual, unfortunately no one so far can use level 3 and level 3 in the same deck.
I will prefer Sign Magick to The Hierophant • V for the Fast Aspect, to keep the Tarot slot free for Four of Cups, and most importantly for a free trigger of spells: You killed an enemy, get a free investigation, you didn't kill the enemy, get an extra attack or an evade to dodge the damages.