Is it something equipment--ish like Holy Armor or Flaming Blade
I think for a deck that embraces flooding the field with characters and bouncing would-be-banished characters back to your hand, the cards that let you heal (which are almost never useful in any trading card game) are wasted space here
Prowling Geistcatcher released to little applause, and is still somehow only a 50 cent card, which is puzzling to me
Both the Gargoyles characters and added hand manipulation effects are refreshing to see in this new set
3 Ulamog, The Infinite Gyre (Textured Foil) $228.92 The most valuable of the Eldrazi Titans can destroy any target permanent just for being cast, which while expensive makes it an excellent removal spell-come-devestarting-10/10-creature
Powerful card selection and the draws are very desirable in blue decks, no matter the format