- "The whole world is watching us. Because if these cannons don't do the trick, then it's all over. At the same time, many people have started to realize their offensive potential. If anything happens, we sure won't be sitting and doing nothing."
- ― Slash commenting on Stonehenge
John Herbert (also known as John Harvard in previous games), callsign Slash, was a mercenary pilot who fought in the Usean Continental War. He signed on with the Scarface Squadron when Operation Fighter's Honor came into effect, and accompanied Phoenix on certain missions.
Shortly after the war's end, he left the Usean Allied Forces and returned to his birthplace in central Usea. He was later offered a position in the Stonehenge Guard Squadron. During his interview for the position, he was busy chatting with the maintenance crew. He also had meals with Dr. Yang Tomic whenever they were both on daytime duty.
He excels as a pilot, but lacks leadership skills and prefers supporting roles instead. His hobbies include tinkering with cars. He also converted an empty hangar into his own personal garage. It is also implied that he is a womanizer according to his in-game dialogue.
- There is much confusion about the true identity of Slash in Ace Combat 2 due to the following two names being given:
- It is likely that, as with the name of the rebellion (retconned as the Usean Continental War), Slash's surname was originally Harvard but retconned to Herbert in Legacy.
- Due to the conflicting situation, Acepedia officially considers John Herbert to be the name of the pilot that flew with Phoenix as well as in the Stonehenge defense squadron, and John Harvard to strictly be the name of the Arkbird astronaut. It is up to our readers to have differing opinions or headcanons considering all available information.