Reynard
Cosmic Mongoose
If you plan to use the 3I universe for your campaign background, remember that background flavor is robots and the Shudusham Concords which reflects a centuries long mistrust with privately owned weaponized 'bots. The Concords have no legal force but was and is a model for worlds with enforced robotic laws. The Imperium is as diverse with robotics as with so many other factors. The biggest rule though on many worlds is robots are owned and the owner in ultimately responsible for the actions of the robot. If the robot fires a weapon, the consequences of the law are solely against the owner.
Build a robot character from Robots. I would suggest a TL 13+ 'bot with a Personality Program of 3 plus an Emotion Generator so it has personality ability close to a player character. Rather than add weapons other than maybe the Electroshock touch to justify a bodyguard role, you can hand it a weapon when other situations prevail just like other organic characters. The players should determine who is the owner whether one person or the team as a whole just like ship ownership. Should be very playable and make for interesting situations such as the general distaste by the patrons in the starport bar on a backwater lower level world.
Build a robot character from Robots. I would suggest a TL 13+ 'bot with a Personality Program of 3 plus an Emotion Generator so it has personality ability close to a player character. Rather than add weapons other than maybe the Electroshock touch to justify a bodyguard role, you can hand it a weapon when other situations prevail just like other organic characters. The players should determine who is the owner whether one person or the team as a whole just like ship ownership. Should be very playable and make for interesting situations such as the general distaste by the patrons in the starport bar on a backwater lower level world.