[@Shoryu Magami]

Here's how my head has laid this down. Cosmos will be the opening post. She'll have hesitated to summon her warriors out of guilt for dragging them into her war, but will eventually do so.

Meanwhile, Chaos will have already summoned his warriors. While talking to Marche, The Emperor will have done the Heir of Hell contract with him. Immediately after, he'll interfere in the summoning of Cosmos's warriors by scattering them. Thoughts?