Throw in the Warsuit, and it’s safe to say that Lex was not kidding around when it came to stocking his strongholds with anti-alien weaponry.
Given that this seemed to be just one of many safe houses, we can bet that Lex has other stashes of dangerous items that will pop up at very inconvenient times for our Girl of Steel.
We already saw back in Season 1 that a Black Mercy parasite can actually cause the death of a Kryptonian, and DC Comics fans know the Atomic Axe as a weapon (usually wielded by the villainous Persuader) that can cut through just about anything.