Pillar of War — ruling 1

Defender only matters when Pillar of War could be declared as an attacking creature. If Pillar of War is already attacking, it becoming not enchanted doesn’t cause it to be removed from combat.

Pillar of War : règles, fonctionnement et interactions (MTG)

Pillar of War is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Defender As long as this creature is enchanted, it can attack as though it didn't have defender.

How it works : Pillar of War

Original English text — Wizards of the Coast / Scryfall

#1February 1, 2014· Wizards of the Coast
Defender only matters when Pillar of War could be declared as an attacking creature. If Pillar of War is already attacking, it becoming not enchanted doesn’t cause it to be removed from combat.
No other card is named in this ruling.