It's worth mentioning that the black lion armor was destroyed by Daimon a moment ago, the reason is simple, the "four heavenly kings", namely, that sole remaining wraith from the mind burning hell, the golden imp from the mountain hell, the leader of the royal devil guards from the throne hell and the black lion armor from the beast colosseum had all become a part of Marcus's domain, therefore when Daimon destroyed the domain not only the castle went down but also those four in a single go.
That being said, they weren't dead yet, based on the four different energy signs coming from Marcus's gauntlets.
"Royal Black Devil Contract, Revocation!", while bleeding from basically all his body, Marcus casted a spell which resulted in one of the four energy signs disappeared.
