As long as Nagustai doesn't receive information, Mort is just missing. Why is he missing? You have to ask the Gray Divine Star about that; before the connection was severed, he reported encountering the Gray Divine Star.
Probably, even the Gray Divine Star couldn't imagine exploding out of nowhere, while Mort was simply on his way and also got caught in this mess.
At this moment, Mort also fell into utter despair. You could almost say that encountering any enemy wouldn't make Mort despair.
For a Void War Tree Man like him, it's very difficult to be exterminated. On the Chaos Plane, the one Ange encountered was down to half a face yet still wasn't completely dead, which shows just how tenacious the life force of Tree People is.
Even if it's completely withered wood, new buds can sprout again in the spring.
So Mort doesn't fear battle; even if his shell is shattered or his tree heart is blown apart, it doesn't matter. Next year, he might sprout and grow stronger branches again.
