Mind Control (group) – The ability to control the minds of four or more people at the same time.
Karma (Marvel) has a brother that is able to control the all Fantastic Four at the same time (Marvel Team-Up #100)!
In Adventure Comics V1 #349, Universo (DC) was almost able to control six legionnaires at the same time. This includes Saturn Girl (DC) and she is a powerful telepath and presumably has some immunity to mind control.
Peter “Sting” Stanchek (Valiant) uses his mind control to kill hundreds of rebels but feels guilty.
Starro (DC) can control the minds of billions of minds at the same time (Who’s Who in the DC Universe #13).
Solovar (DC) – Injustice 2 #43