Most played cards in Rakdos:

1 Decks
Inquisition of Kozilek
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Ball Lightning
4 copies - 4 average
Faithless Looting
4 copies - 4 average
Lightning Skelemental
4 copies - 4 average
Thoughtseize
4 copies - 4 average
Unearth
4 copies - 4 average
Thunderkin Awakener
4 copies - 4 average
Cavern of Souls
4 copies - 4 average
Blackcleave Cliffs
4 copies - 4 average
Lightning Mare
3 copies - 3 average
Red Elemental Blast
3 copies - 3 average
Chain Lightning
3 copies - 3 average
Blood Crypt
3 copies - 3 average
Alpine Moon
2 copies - 2 average
Leyline of the Void
2 copies - 2 average
Bloodstained Mire
2 copies - 2 average
Snow-Covered Mountain
2 copies - 2 average
Shenanigans
2 copies - 2 average
Polluted Delta
2 copies - 2 average