Cathedral Membrane
Artifact Creature — Phyrexian Wall
( can be paid with either 
or 2 life.)
Defender
When this creature dies during combat, it deals 6 damage to each creature it blocked this combat.
Richard Whitters
New Phyrexia (NPH)
• #5Rulings
As you cast a spell or activate an activated ability with one or more Phyrexian mana symbols in its cost, you choose how to pay for each Phyrexian mana symbol at the same time you would choose modes or choose a value for X.
(wotc • 2011-06-01)
If you're at 1 life or less, you can't pay 2 life.
(wotc • 2011-06-01)
A card with Phyrexian mana symbols in its mana cost is each color that appears in that mana cost, regardless of how that cost may have been paid.
(wotc • 2011-06-01)
Phyrexian mana is not a new color. Players can't produce Phyrexian mana.
(wotc • 2011-06-01)
Cathedral Membrane's ability will trigger no matter why it's put into a graveyard during the combat phase, not just because of combat damage.
(wotc • 2011-06-01)
To calculate the mana value of a card with Phyrexian mana symbols in its cost, count each Phyrexian mana symbol as 1.
(wotc • 2011-06-01)
Rulings
As you cast a spell or activate an activated ability with one or more Phyrexian mana symbols in its cost, you choose how to pay for each Phyrexian mana symbol at the same time you would choose modes or choose a value for X.
(wotc • 2011-06-01)
If you're at 1 life or less, you can't pay 2 life.
(wotc • 2011-06-01)
A card with Phyrexian mana symbols in its mana cost is each color that appears in that mana cost, regardless of how that cost may have been paid.
(wotc • 2011-06-01)
Phyrexian mana is not a new color. Players can't produce Phyrexian mana.
(wotc • 2011-06-01)
Cathedral Membrane's ability will trigger no matter why it's put into a graveyard during the combat phase, not just because of combat damage.
(wotc • 2011-06-01)
To calculate the mana value of a card with Phyrexian mana symbols in its cost, count each Phyrexian mana symbol as 1.
(wotc • 2011-06-01)