An undeniably lovely alternative or companion to Acidic Ichor. It works especially well for Minh Thi Phan, who should be built around card-draw abilities anyway, but basically any Seeker would be glad to have this, if they can spare the hand-slots for it.
Remember that attacks of opportunity are resolved before the effects of the action that triggered them, so simply taking a normal draw to deal the last point of damage on an enemy isn't ideal. Consider having a partner engage it before your turn begins.
Knowledge of the Elders makes most of your cards with drawing effects better, including innate skills like Perception, but the clearest benefit comes from Cryptic Research, which temporarily turns Knowledge into a fast automatic three damage. You should also insist your partner get Stand Together, if able, and you might likewise be interested in Lucky Cigarette Case. I don't think I'd bother with Preposterous Sketches or Laboratory Assistant in the current mix, but maybe there's a way to make them worthwhile? If some future card comes up with a recurring ability to draw 2 cards (like, say, a Seeker-ish variant of Dario El-Amin that gets cards instead of resources), Knowledge will truly be power.
Bringing this "weaponized draws" concept back to Minh for a moment, Analytical Mind plus any successful innate skill means two card-draws, and she can get those draws by contributing to another investigator's skill-check anywhere on the table. In fact, if Minh ever has Analytical Mind and Knowledge in play, have her draw the first encounter card - there's a decent chance she can draw and kill an enemy before the Investigation phase even begins!
The main alternatives we need to discuss are Acidic Ichor and Minds in Harmony. The more important of these is Ichor.
The hand-slot requirement might be a deal-breaker for Daisy Walker, but I don't think the hand-slots are a huge deal for other Seekers. Magnifying Glass is nice; Flashlight isn't usually a Seeker favourite; Encyclopedia is nice, although some of its utility has been absorbed by Higher Education; most other tomes aren't that important. In fact, even Daisy might eventually settle on using only Encyclopedia for her free tome action, so even for her Knowledge isn't totally out of the question.
Notably, Knowledge is vastly better than Ichor for dealing with aloof enemies, such as Whippoorwill. It's also nice to have a way to trivially remove Acolyte, and many other one-health enemies, for just one secret. Those enemies also tend to deal low damage, so it's often easiest just to draw your card and take the attack of opportunity.
I think Knowledge and Ichor are on roughly equal footing. Knowledge is slightly more powerful, given its reliability and its ability to function without necessarily taking actions, but Ichor is more versatile, and can yield a greater amount of damage across the scenario, especially if you're willing to commit to Level 3 Emergency Cache. Ichor's also the better pick against boss enemies for its ability to deal lots of damage in one turn, but if you're playing alongside someone who can get Lightning Gun, M1918 BAR, or Chicago Typewriter, maybe that doesn't matter so much. It's probably safe to say "Ichor on Normal, Knowledge on Expert," although in either case I'd want to eventually get both.
I have a slight preference for Knowledge of the Elders over Minds in Harmony, given that horror-removal is less likely to be useful to a Seeker than auto-damage in a random hypothetical scenario, but I don't think it's a slam dunk in the same way as, say, Acidic Ichor over the other Strange Solutions. If I were to draw two Harmonies using Shrewd Analysis, I'd shrug rather than gnash my teeth.