Picking 10 is tough...
Death of Firstborn - a versatile card that's a "better" Striking Herod for angels.
Elijah - Long overdue reprint with a super solid ability.
Elisha - same as Elijah.
Sheol - one of my favorite cards in play testing and why it got my vote for UR.
Lacking Prophecy - I love flavor of this card and having strong "in set counters" to a sets strong themes.
Necromancer - another card with strong flavor and a unique ability.
The Fallen Star - such a boss! Reminds me of my love for PotW and KoT back when I started playing.
Persian Horsemen - unique and versatile in a theme that needed bolstering.
False Leaders - really enjoyed testing this card.
Treacherous Land - another card I enjoyed testing. It often gets targeted by 3W.
Lost Soul "Remnant" - a really great card that changes games. Also why it got my vote for UR.
The Terrifying Beast - truly terrify and fun to play with.
Eternal Judgment - another flavorful card that's skill intensive and really fun in MP.
Day of the Lord - part 2 of a 3 part series, it has a strong * and a strong SA.
Pagan Sailors - flavorful, fun and fairly unique. Allows for so many cool tricks.
Jonah - go ahead, make my day, search...
The Emmaus Road - this is what the whole set is all about!
Faith - really cool player made card that makes cloud fun a 2nd time around.
Sorry, that's 18 but I didn't want to narrow it down.