Rex had only seen Princess Davina fight a few times.
And the clearest display of power that he saw her use was back when he saw her for the first time.
From the notifications he gained at that time, Princess Davina surely has multiple Echoes assimilated into her Soul Artifact. As someone who was deemed a super genius, a pillar for the new generation, she surely has a high-grade Soul Artifact, and thus, having multiple Echoes is not that surprising.
Even Rex has two Echoes within the Red Dawn of Kaiser.
It was the Dark Auctoritas Echo and the Blood Moon Echo.
But his main goal was now the latter as his breakthrough to the Eternal Spirit rank was through that one.
Moreover, considering the grade of the Red Dawn of Kaiser, he could probably add more Echoes.
Not that he would, though.
