Scott "Bean" Wollinski was born to simple bean farmers, raised by his father until he was 15, who then sold him to a caravan merchant hoping he would have a better life. He traveled with the caravans for a few years working as an indentured servant. This is where he got the nickname "Bean," because his purchase was paid for with beans. He eventually bought his freedom and settled down in Canterbury Commons, where he lived a life of solitude, hiding in the electronics store, fiddling around with junk. After the AntAgonizer started showing up, he became the Mechanist to protect the town.
He will attack you if he finds out that you work for the AntAgonizer (or if he suspects that you are working for her). However, if you convince him you are not a secret agent, you can work with him. Not giving him the AntAgonizer's suit however will also cause him to attack you.
It is possible to keep both sets of armor and Protectron's Gaze by Reverse-Pickpocketing. First, convince the AntAgonizer to give up using the Lady Killer perk or a speech check. Then, go to the Mechanist, but drop the AntAgonizer's costume and helmet before talking to him. He will say his spybots tell him the AntAgonizer is defeated but he needs the armor. Pick up only the AntAgonizer's Costume; he doesn't require the helmet, and will actually duplicate one in his inventory. Using a Stealth Boy, if needed, sneak and give him both a combat helmet and combat armor, leave the building, and go back in. While still stealthed, tell the Mechanist he can have the costume but to "move on and leave Canterbury alone". As he walks away, sneak up to him and take both sets of armor from his inventory, including the extra helmet. Note you will receive the usual penalty to Karma when pickpocketing.
Another way to keep both costumes and Protectron's Gaze is to give The Mechanist the AntAgonizer's costume, then after he gives you Protectron's Gaze, kill him and loot both costumes
Surprisingly, the Mechanist is not allied with the robots in his Robot Repair Center, and will fight them (and most likely be killed by them) if he ever crosses path with one.
After you deal with the Mechanist, either by giving him the AntAgonizer's costume or convincing him to retire, he'll leave the Robot Repair Center and walk out into the Wastes. He'll simply disappear from the map if he gets too far away from you. If the player follows, he/she will eventually see that the Mechanist's destination is the 'backdoor path' to the AntAgonizer's lair. When arriving there the Mechanist will just stand near the entrance. If the player approaches him, the Mechanist will start the conversation saying that he wants to be left alone.
Female characters with the Black Widow perk can choose an additional dialogue option to acquire The Mechanist's costume peacefully. Male characters can use the Child at Heart perk instead to convince the Mechanist to give up the position of a superhero.