Will Evaan appeared at the scene of the battle using a space-element array.
He was accompanied by Renar, Viper, and Seref. Seref was a D-Rank plant monster Will, Renar, and Viper had trained. Under their guidance and with the right resources, Seref had transformed himself into a functional member of the rankers' society.
Eren had already left the place with Alephee, Argo, and Sienna. He had given Will's team all the instructions they needed to create a royal conspiracy. He had left the living undead Meera on the battlefield. Krista's team was supposed to be killed by her hand.
Meera had worn a mask to cover her face. Alephee had cast her own magic on her that wouldn't make her come across as a living undead. Will was instructed to deliver Krista, Lambert, and Ruper to her and she would take care of them using instructions imprinted on her consciousness by Eren.