アーティファクト — 装備品
装備しているクリーチャーは、対戦相手1人につき+1/+0の修整を受ける。
装備しているクリーチャーがダメージを受けるたび、クリーチャー1体かプレインズウォーカー1体かプレイヤー1人を対象とする。装備しているクリーチャーはそれに、その点数に等しい点数のダメージを与える。
装備

A creature can be dealt an amount of damage greater than its toughness. For example, if the equipped creature has 1 toughness and is dealt 3 damage, it deals 3 damage, not 1, to the chosen target.
If your life total is brought to 0 or less at the same time that the equipped creature is dealt damage, you lose the game before Blazing Sunsteel's middle ability goes on the stack.
Blazing Sunsteel is the source of the middle triggered ability, but the equipped creature is the source of the damage. For example, if the equipped creature is green, that ability can't target a permanent with protection from red, but it can target one with protection from green, though the damage would be prevented.
Opponents who have left the game aren't counted by Blazing Sunsteel's first ability.