Most played cards in Ascension Combo:

4 Decks
Manamorphose
16 copies - 4 average
Ponder
16 copies - 4 average
Preordain
16 copies - 4 average
Scalding Tarn
16 copies - 4 average
Punishing Fire
16 copies - 4 average
Mana Leak
16 copies - 4 average
Pyromancer Ascension
16 copies - 4 average
Grove of the Burnwillows
16 copies - 4 average
Lightning Bolt
16 copies - 4 average
Cryptic Command
16 copies - 4 average
Cascade Bluffs
15 copies - 3.75 average
Time Warp
14 copies - 3.5 average
Spell Pierce
9 copies - 2.25 average
Shivan Reef
9 copies - 2.25 average
Pithing Needle
9 copies - 2.25 average
Negate
8 copies - 2 average
Pestermite
8 copies - 2 average
Splinter Twin
8 copies - 2 average
8 copies - 2 average
Volcanic Fallout
7 copies - 1.75 average