Phyrexian Crusader

First strike is a static ability that modifies the rules for the combat damage step. (See rule 510, “Combat Damage Step.”)

If at least one attacking or blocking creature has first strike or double strike (see rule 702.4) as the combat damage step begins, the only creatures that assign combat damage in that step are those with first strike or double strike. After that step, instead of proceeding to the end of combat step, the phase gets a second combat damage step. The only creatures that assign combat damage in that step are the remaining attackers and blockers that had neither first strike nor double strike as the first combat damage step began, as well as the remaining attackers and blockers that currently have double strike. After that step, the phase proceeds to the end of combat step.

Giving first strike to a creature without it after combat damage has already been dealt in the first combat damage step won’t preclude that creature from assigning combat damage in the second combat damage step. Removing first strike from a creature after it has already dealt combat damage in the first combat damage step won’t allow it to also assign combat damage in the second combat damage step (unless the creature has double strike).

Multiple instances of first strike on the same creature are redundant.

Protection is a static ability, written “Protection from [quality].” This quality is usually a color (as in “protection from black”) but can be any characteristic value or information. If the quality happens to be a card name, it is treated as such only if the protection ability specifies that the quality is a name. If the quality is a card type, subtype, or supertype, the ability applies to sources that are permanents with that card type, subtype, or supertype and to any sources not on the battlefield that are of that card type, subtype, or supertype. This is an exception to rule 109.2.

A permanent or player with protection can’t be targeted by spells with the stated quality and can’t be targeted by abilities from a source with the stated quality.

A permanent or player with protection can’t be enchanted by Auras that have the stated quality. Such Auras attached to the permanent or player with protection will be put into their owners’ graveyards as a state-based action. (See rule 704, “State-Based Actions.”)

A permanent with protection can’t be equipped by Equipment that have the stated quality or fortified by Fortifications that have the stated quality. Such Equipment or Fortifications become unattached from that permanent as a state-based action, but remain on the battlefield. (See rule 704, “State-Based Actions.”)

Any damage that would be dealt by sources that have the stated quality to a permanent or player with protection is prevented.

Attacking creatures with protection can’t be blocked by creatures that have the stated quality.

“Protection from [quality A] and from [quality B]” is shorthand for “protection from [quality A]” and “protection from [quality B]”; it behaves as two separate protection abilities.

“Protection from each [characteristic]” is shorthand for “protection from [quality A],” “protection from [quality B],” and so on for each possible quality the listed characteristic could have; it behaves as multiple separate protection abilities.

“Protection from each [set of characteristics, qualities, or players]” is shorthand for “protection from [A],” “protection from [B],” and so on for each characteristic, quality, or player in the set. It behaves as multiple separate protection abilities.

“Protection from everything” is a variant of the protection ability. A permanent or player with protection from everything has protection from each object regardless of that object’s characteristic values. Such a permanent or player can’t be targeted by spells or abilities and can’t be enchanted by Auras. Such a permanent can’t be equipped by Equipment, fortified by Fortifications, or blocked by creatures. All damage that would be dealt to such a permanent or player is prevented.

“Protection from [a player]” is a variant of the protection ability. A permanent or player with protection from a specific player has protection from each object that player controls and protection from each object that player owns not controlled by another player, regardless of that object’s characteristic values. Such a permanent or player can’t be targeted by spells or abilities the specified player controls and can’t be enchanted by Auras that player controls. Such a permanent can’t be equipped by Equipment that player controls, fortified by Fortifications that player controls, or blocked by creatures that player controls. All damage that would be dealt to such a permanent or player by sources controlled by the specified player or owned by that player but not controlled by another player is prevented.

Multiple instances of protection from the same quality on the same permanent or player are redundant.

Some Auras both give the enchanted creature protection from a quality and say “this effect doesn’t remove” either that specific Aura or all Auras. This means that the specified Auras aren’t put into their owners’ graveyards as a state-based action. If the creature has other instances of protection from the same quality, those instances affect Auras as normal.

One Aura (Benevolent Blessing) gives the enchanted creature protection from a quality and says the effect doesn’t remove certain permanents that are “already attached to” that creature. This means that, when the protection effect starts to apply, any objects with the stated quality that are already attached to that creature (including the Aura giving that creature protection) will not be put into their owners’ graveyards as a state-based action. Other permanents with the stated quality can’t become attached to the creature. If the creature has other instances of protection from the same quality, those instances affect attached permanents as normal.

Infect is a static ability.

Damage dealt to a player by a source with infect doesn’t cause that player to lose life. Rather, it causes that source’s controller to give the player that many poison counters. See rule 120.3.

Damage dealt to a creature by a source with infect isn’t marked on that creature. Rather, it causes that source’s controller to put that many -1/-1 counters on that creature. See rule 120.3.

If an object changes zones before an effect causes it to deal damage, its last known information is used to determine whether it had infect.

The infect rules function no matter what zone an object with infect deals damage from.

Multiple instances of infect on the same object are redundant.