The battlefield was expanded and divided into many smaller parts.
Ivor looked busy handling his share of rankers in the pseudo-lightning domain. Eren's summons kept the remaining rankers busy until Ivor was done with his ongoing assignments.
Meanwhile, Meera forced Oliver to take their fight to a different zone under Eren's orders. He coordinated with Layla and lowered the prism barrier just at the right time before springing it back up, making Meera leave the isolated zone along with Oliver.
The butcher didn't want the duel between two Expert rankers to disturb his summons and prevent them from doing their job. Plus, he didn't want Oliver to assemble his team under his orders again.
When all this was done, Eren was left to choose the opponent he wanted to target. He glanced across the region and narrowed his eyes to a single man who was destroying his summons before they had a chance to fully recuperate.
Blitz Bolt