Based on comments by reviewers of the Quantum Generator Challenge, it looks like this does need a rework before sending it off to crucible. Possible variations:
A) 1: Discard target card from hand. Gain quanta based on card's casting cost.
(Note: In this variation, cards costing from 0-3 quanta would give 3 random, 1 matching mark, 4-7 would give 4 & 2 respectively, and 8+ would give 5 & 3.)
B) 1: Discard target card from hand. Gain quanta based on card's casting cost.
(In this variation, the whole casting cost would be granted, half random and half (rounding down) to match your mark.)
C) 3: Discard target card from opponent's hand. Gain random quanta equal to card's casting cost.
(A lot more offensive, high activation cost to mitigate multiple Magpies. Ties in to Precognition and Mindgate, and forces the opponent to play any card drawn later in the game or face it being disposed of. Can also be coupled with Silence to guarantee a bit of denial.)
A & B above may look alike, but the difference between the two is that A favors discarding low cost cards for a quick profit, while B favors loading your deck with high cost cards. C takes it into a whole new area, and does tie into the theme of the Magpie a little bit more.
Edit: C could also be changed to read "3: Discard target card from either player's hand. Gain random quanta equal to card's casting cost." Makes it useful even if the opponent is managing to play everything.