Cast Eternal Scourge by paying ({3} magic symbol) .
Activate Blade of Shared Souls' equip ability by paying ({2} magic symbol) , attaching it to Eternal Scourge.
Blade of Shared Souls triggers, causing Eternal Scourge to become a copy of Gerrard.
Put Eternal Scourge into your graveyard due to the legend rule.
When Eternal Scourge dies as a copy of Gerrard, it triggers, exiling itself and returning all other artifact and creature cards put into your graveyard this turn to the battlefield.