I'm going to give this a try in Patrice Hathaway. It's a cheap spell she can get out that helps her deal with Watcher from Another Dimension. Plus, you get extra actions. I really really like extra actions to deal with hidden weaknesses / weaknesses / playing the things in your hand.
I'm also going to give this a try in Leo Anderson. Leo's lack of innate evasion where sometimes it is required makes this kinda a really interesting choice. HMMM. What a weird investigator.... uses Willpower from Guardian statline on a Rogue/Mystic card that lets you use agility, but Leo takes advantage of the card pool access...