Superheavy Samurai Soulshield Wall

The monster effect "①: During your Main Phase: You can target 1 'Superheavy Samurai' monster you control; equip this monster from your hand or field to that target as an Equip Card that increases its DEF by 1200" is an Ignition Effect. (This effect targets 1 face-up "Superheavy Samurai" monster you control.)

The effect "(2): When a monster equipped with this card by this card's effect is selected as an attack target: You can send this equipped card to the GY; negate that attack, and if you do, change the equipped monster's DEF to 0" is treated as an effect that occurs while this card is treated as an Equip Spell Card. (This effect activates and creates a Chain Link.)

The effect "negate that attack" and the effect "change the equipped monster's DEF to 0" are treated as occurring simultaneously.