A permanent that’s both a blocking creature and a planeswalker that’s being attacked is removed from combat if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that’s being attacked, whichever is appropriate.
January 25, 2019 · Ravnica Allegiance
A permanent that's both a blocking creature and a planeswalker that's being attacked is removed from combat if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that's being attacked, whichever is appropriate.
February 1, 2014 · Born of the Gods
A permanent that’s both a blocking creature and a planeswalker that’s being attacked is removed from combat if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that’s being attacked, whichever is appropriate.
February 1, 2013 · Gatecrash
A permanent that's both a blocking creature and a planeswalker that's being attacked is removed from combat if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that's being attacked, whichever is appropriate.
September 30, 2011 · Innistrad
A permanent that's both a blocking creature and a planeswalker that's being attacked is removed from combat only if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that's being attacked, whichever is appropriate.
June 17, 2011 · Commander 2011
A permanent that’s both a blocking creature and a planeswalker that’s being attacked is
April 1, 2011 · Duel Decks: Knights vs. Dragons
A permanent that's both a blocking creature and a planeswalker that's being attacked is removed from combat only if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that's being attacked, whichever is appropriate.
February 4, 2011 · Mirrodin Besieged
A permanent that’s both a blocking creature and a planeswalker that’s being attacked is removed from combat only if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that’s being attacked, whichever is appropriate.
October 1, 2010 · Scars of Mirrodin
A permanent that’s both a blocking creature and a planeswalker that’s being attacked is
February 1, 2010 · Worldwake
A permanent that's both a blocking creature and a planeswalker that's being attacked is removed from combat only if it stops being both a creature and a planeswalker. If it stops being one of those card types but continues to be the other, it continues to be either a blocking creature or a planeswalker that's being attacked, whichever is appropriate.