Most played cards in Helm Combo:

1 Decks
Leyline of the Void
4 copies - 4 average
Agadeem's Awakening
4 copies - 4 average
Ancient Tomb
4 copies - 4 average
Helm of Obedience
4 copies - 4 average
Karn, the Great Creator
4 copies - 4 average
Dark Ritual
4 copies - 4 average
Chrome Mox
4 copies - 4 average
City of Traitors
4 copies - 4 average
Orcish Bowmasters
4 copies - 4 average
Dauthi Voidwalker
4 copies - 4 average
Opposition Agent
4 copies - 4 average
Thoughtseize
3 copies - 3 average
The One Ring
3 copies - 3 average
Grief
3 copies - 3 average
Plague Engineer
2 copies - 2 average
Sheoldred, the Apocalypse
2 copies - 2 average
Powder Keg
1 copies - 1 average
Faerie Macabre
1 copies - 1 average
Trinisphere
1 copies - 1 average
Mycosynth Lattice
1 copies - 1 average