He charges them so the player can escape with the Mag'har, but then you are ported and you never see the outcome. Logically speaking he would most surely die against such a force, but logically speaking he should have died at the end of WoD... so...
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It mentions it in the Mag'har chain. The Lightbound and Mag'har are blaming each other. The Lightbound blame the orcs, which is why they want to convert them, and the Mag'har say it is the Lightbound and their Light that is actually killing the land.