How is Sphinx for you?
Sphinx of Foresight vs
Ponder
-both filter through your top 3 cards and can get rid of all
-Sphinx saves one blue mana
-Sphinx doesn't cost a card but also doesn't put the card in hand (card neutral?)
-Ponder is +1 graveyard size, Sphinx doesn't add to GY
-Ponder digs beyond turn 1 and is a great topdeck
-Sphinx can be cast lategame as a creature... if we get to 4 mana AND care about dealing the opponent damage, otherwise it sits dead in hand
-both pitch to FoW
-Sphinx is good fodder for Gamble discard. padding hand size with a disposable card
It might be better than Serum Powder but don't know it's worth playing before Ponder.