It would be a start to explain who he is, in flashbacks perhaps, what his realm looked like before his banishment how his followers looked like before everything changed, but there is still nothing explaining that, he just got a mawsworn armor and thats it.
He has less lore than the Thunderking...
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Blizzards pull a J.J. Abrahms direction, same story in latest star wars intallments, putting stuff that makes no sense into the lore without explanation is the new cool. Yet, it does not create that sweet feeling of mystery, but only confusion and offense.