To give a bit of info on each:
The Hidden master is a summoner archetype that focuses on using the eidolon at great distances allowing the summoner both safety and anonymity at the cost of convenience and capability.
The Laughing avenger is a mesmerist pulled straight from pulp fiction and inspired by The Shadow as a psychic who can leave his foes bewildered and terrified.
lastly the masked rider is a cavalier that pulls from the traditional stories of disguised knights and mounted heroes who do deeds of valor or villainy from a diguise.