You choose the target as part of casting the spell. You choose what attribute the target gains protection from when the spell resolves.

Phyrexian mana is not a new color. Players can't produce Phyrexian mana.

If you're at 1 life or less, you can't pay 2 life.

To calculate the mana value of a card with Phyrexian mana symbols in its cost, count each Phyrexian mana symbol as 1.

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.

Any Equipment attached to a creature that gains protection from artifacts will become unattached.

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.