The crow was furiously attacking that shield.
At first when he left Arthur he was totally enraged by what happened. He knew part of this wasn't Arthur's fault, but the thought of everyone going back to the higher realms and fighting for their own clans except for him drove him mad.
After some time he started to chill out a bit. And yet he didn't totally believe what he heard. He started to follow Arthur from far, waiting to see if what he said was true or not.
If this world involved many great dark forces as he claimed or not.
When that pagoda appeared, his heart told him that Arthur was right. However even before he could act, Arthur already vanished along with that pagoda and portal.
He tried to look for him but there was no single trace left. It was like Arthur himself vanished.
Before he could settle on what happened or what he should do, the great war broke off and he saw them.
