Why was Black Panther named "King of the Dead"?

[XPac]

Well wouldn't you say him beating Black Dwarf shows what we believe was his power level given the difficulty in taking him down by all the X-men?

Sort of like Spider-man vs the Juggernaut.

I don't believe Black Dwarf fought all the X-Men.

But that aside, the because the Black Panther fight was entirely off panel it's really hard to say anything about what happened here.