Batman. He is in street clothes.
Round 1) He has no gear.
Round 2) He has Batrangs and grappling hook.
VS
Black widow. Hawkeye. Okoye. Falcon. Bobbi Morse. Melinda May. Grant Ward. Phil Coulson. Ironfist. Davos. Coleen. Misty Knight. Daredevil. Stick. Punisher. Mary Walker. Nuke. Trish. Jigsaw. Agent Madani. Crossbone
MCU has standar gear. Except Falcon has no missile or red wing. Edit: I forgot to mention no Chi abilities for Danny, Davos or Coleen.
Can all these humans working together defeat Batman?
Does it make a difference if the fight is in the arena or Gotham?