Slight spoiler......
He is the ultimate Nomu, the reason it's a slight spoiler is because there were already quite some tips for it in the latest chapters.
He is called Best Jeanist, thank you anyway though <3
"All Might, There is blood over here!" Best Jeanist yelled which shook All Might out of his thoughts and looked at Best Jeanist who suddenly froze up in the doorway where the trail of blood was leading too.