If a creature has multiple instances of flanking, each triggers separately.
May 3, 2019 · War of the Spark
If a permanent phases out, its status changes to “phased out.” Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can’t affect or be affected by anything else in the game. A permanent that phases out is removed from combat. (See rule 506.4.)
January 25, 2019 · Ravnica Allegiance
If a permanent phases out, its status changes to "phased out." Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can't affect or be affected by anything else in the game. A permanent that phases out is removed from combat. (See rule 506.4.)
January 16, 2016 · Oath of the Gatewatch
If a permanent phases out, its status changes to “phased out.” Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can’t affect or be affected by anything else in the game. A permanent that phases out is removed from combat. (See rule 506.4.)
May 1, 2014 · Journey into Nyx
If a permanent phases out, its status changes to “phased out.” Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can’t affect or be affected by anything else in the game.
February 1, 2014 · Born of the Gods
If a permanent phases out, its status changes to "phased out." Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can’t affect or be affected by anything else in the game.
July 13, 2013 · Magic 2014
If a permanent phases out, its status changes to "phased out." Except for rules and effects that specifically mention phased-out permanents, a phased-out permanent is treated as though it does not exist. It can't affect or be affected by anything else in the game.
June 17, 2011 · Commander 2011
rule 702.25b not present in this release
April 1, 2011 · Duel Decks: Knights vs. Dragons
A creature with shadow can't be blocked by creatures without shadow, and a creature without shadow can't be blocked by creatures with shadow. (See rule 509, "Declare Blockers Step.")
February 4, 2011 · Mirrodin Besieged
A creature with shadow can’t be blocked by creatures without shadow, and a creature without shadow can’t be blocked by creatures with shadow. (See rule 509, “Declare Blockers Step.”)
October 1, 2010 · Scars of Mirrodin
A creature with shadow can’t be blocked by creatures without shadow, and a creature
February 1, 2010 · Worldwake
A creature with shadow can't be blocked by creatures without shadow, and a creature without shadow can't be blocked by creatures with shadow. (See rule 509, "Declare Blockers Step.")