Dark Nights: Metal # 2 Explains What “Metal” Means
So while we never really got why “Metal” was an important topic and the driving force behind the new DC Comics event book, Dark Nights: Metal # 2 gives both casual readers and long-time fans a solid explanation and it all involves Batman.
So based on Batman’s explanation after Superman and Wonder finally catch up to him; this was after the Justice League and other heroes started a Batman manhunt in the opening pages of Dark Nights: Metal # 2.
So while this is all a trick on Bruce’s part (spoiler: This was actually Clayface) what “Batman” was telling Clark and Diana were actually true.
Barbatos had the “Judas Tribe” insert various metals into Batman at various points in Bruce’s life. It’s a HUGE call back to Scott Snyder’s work on Batman during the NEW 52 era from all the important volumes like COURT OF OWLS to ENDGAME.
Superman’s too smart and too knowledgeable about Batman that he instantly realizes he’s not talking to Batman at all.
It’s actually Clayface with Batman’s heartbeat and vital signs embedded in him.
So where was Batman all this time?
It took a meeting between Kendra Saunders of the BLACKHAWKS and all the immortals of the DCU in a secret hideout that’s a reference to the classic hideout of the LEGION OF DOOM. There, Kendra realizes that Batman was actually in the Tomb of Hath Seth.
There were five metals that was needed inside Batman’s body to open the Dark Universe and bring in Barbatos. So far the four elements have already been mentioned by Batman and the fifth metal (as explained by the Court of Owls) isn’t available in this universe but rather from the Dark Universe and they called in BATMANIUM.