Display of Dominance — ruling 1

If you choose the second mode, and if a permanent you control is being targeted by a spell when Display of Dominance resolves, nothing happens right away. When that spell would resolve, its color is checked. If it’s blue or black, that permanent will be an illegal target for that spell and won’t be affected by it. If all that spell’s targets have become illegal by the time it would resolve, it’s countered.

Display of Dominance — ruling 2

If you choose the second mode, no new blue or black spell may be cast by an opponent that turn targeting a permanent you control after Display of Dominance resolves.

Display of Dominance — ruling 3

If you choose the second mode, Display of Dominance will affect any permanent you happen to control at any point during the rest of the turn, not just permanents you control as it resolves. That’s because it doesn’t grant an ability to those permanents; rather, it affects the game rules and states something that’s now true about those permanents.

Display of Dominance — ruling 4

Keep in mind that an Aura spell targets the permanent it will enchant (but an Aura on the battlefield doesn’t target the permanent it’s attached to).

Display of Dominance — ruling 5

Permanents you control may be the targets of abilities from blue or black sources controlled by your opponents.

Display of Dominance : règles, fonctionnement et interactions (MTG)

Display of Dominance 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

Choose one — • Destroy target blue or black noncreature permanent. • Permanents you control can't be the targets of blue or black spells your opponents control this turn.

How it works : Display of Dominance

Original English text — Wizards of the Coast / Scryfall

#1February 25, 2015· Wizards of the Coast
If you choose the second mode, and if a permanent you control is being targeted by a spell when Display of Dominance resolves, nothing happens right away. When that spell would resolve, its color is checked. If it’s blue or black, that permanent will be an illegal target for that spell and won’t be affected by it. If all that spell’s targets have become illegal by the time it would resolve, it’s countered.
No other card is named in this ruling.
#2February 25, 2015· Wizards of the Coast
If you choose the second mode, no new blue or black spell may be cast by an opponent that turn targeting a permanent you control after Display of Dominance resolves.
No other card is named in this ruling.
#3February 25, 2015· Wizards of the Coast
If you choose the second mode, Display of Dominance will affect any permanent you happen to control at any point during the rest of the turn, not just permanents you control as it resolves. That’s because it doesn’t grant an ability to those permanents; rather, it affects the game rules and states something that’s now true about those permanents.
No other card is named in this ruling.
#4February 25, 2015· Wizards of the Coast
Keep in mind that an Aura spell targets the permanent it will enchant (but an Aura on the battlefield doesn’t target the permanent it’s attached to).
No other card is named in this ruling.
#5February 25, 2015· Wizards of the Coast
Permanents you control may be the targets of abilities from blue or black sources controlled by your opponents.
No other card is named in this ruling.