"Those who disagree, I challenge them to come forward."
A clap was heard when Eren pitted his palms against each other after he threw his command into the crowd. The monsters were free to discuss at this point. There were no restrictions placed upon them.
Yet, they knew approaching Eren and confronting him had become even more difficult now that Ror was on his side. He was an Ogre Overlord who was a step away from becoming an Ogre King. No other monster was at his level in the audience from any faction.
However, in monster traditions, someone proposing mortal combat was considered sacred. There wouldn't be external support involved in such battles when the challenger himself had thrown a challenge.
At least that's what the audience thought after hearing Eren's words.