Whenever an Equipment enters the battlefield under your control, you may draw a card.
Metalcraft — Equipment you control have equip {0} as long as you control three or more artifacts.
Once the equip {0} ability is activated, causing Puresteel Paladin to leave the battlefield or causing its controller to control fewer than three artifacts won't stop the equip ability from resolving.
You may still activate the Equipment's other equip abilities if you wish.