The Dual-Strike Binarium Stone in Mortal Shell 2 is a very useful special item. To obtain it, start by heading to Widow's Cliff at the beginning of the game. It's recommended to acquire the Assassin Shell before picking it up, as there are numerous enemies along the way. When facing too many foes, consider using stealth to sneak past them.
How to Obtain the Dual-Strike Binarium Stone in Mortal Shell 2