Romani Archaman is introduced as slacking doctor for the Chaldea Security Organization, stuffing his face with a cake. Overall, he's amicable and maybe too lax, but that may be because has very little work to do. You may even call him unreliable (repeatedly), but one can say that he's a cheerful and cordial man when you meet him. Seeing that he wasn't at his office and instead played hooky in an empty room, I wouldn't count on him to be on time. His heart is at least in the right place.

He's friendly, maybe overly friendly. When the protagonist invades his precious time alone, he mentions that they might as well bond while they're here. He also doesn't raise his voice around co-workers, despite how it's common to get insults from them. Even the coy Mashu has it in her to bully and abuse him, but he laughs it off as if it's no trouble. When he isn't laughing, he has some pretty comical responses whether it being depressed or completely glazing over his lack of awareness. Speaking of awareness, Romani may be too comfortable in most environments.

A lot say he's an open book. His expressions are easy to read and he seldom finds reason to hide his thoughts. Not only that, some of his actions and hobbies are pretty questionable for his age. Have you ever had a man reaching 30 unknowingly steal your snack you prepared for yourself and senpai, then seem unapologetic over it? Would you say it's appropriate to tease your superiors and subordinates? Is it offensive to say someone's expressions are amusing to watch? He does it all usually with no regrets. Overall, he's a silly and eccentric man with some strange hobbies. Let's see... He follows a net idol's blog avidly. It's also heavily implied he likes the Magical Girl genre. There has been mentions of shrines for historical figures from Marie Antoinette to Merlin. To say he has shame over it is an overstatement. While he shows respect to his superiors, he can't help but say some unnecessary things at the wrong moments. It doesn't look like he cares too much if people know. In a way, he's brazen. You can say it's a con of honesty. During Singularity F, he isn't afraid to mention Olga's a chicken and he wonders if she'll be able to hold her own. At least he cares?

Though he may have a foot-in-mouth syndrome, he does show genuine concern for others. He voices his worry over Olga's stress and how he would like to help. Likewise, during the singularities, he always presses for our Heroes to rest when they're allowed to. It's really all he can do with the limited amount of influence and power he has as a normal human being. His methods in taking care of others and response to problematic situations, however, are contrary to what most JRPG main characters take. He thinks very carefully about the well-being of others. It's better to be out of danger completely than risk saving others. He's averse to risk and it shows when he's first introduced. When Chaldea crumbles, he tells the protagonist to leave the facility and wait. Of course Romani doesn't take his own advice and instead helps at the site of disaster. He's responsible in that sense.

You can say he's the first one to advocate retreating and avoiding engaging in the enemy if it's possible. It's what he usually recommends, especially when the chances of victory are grim. Romani, despite his cheerfulness, is a realist and pessimist. He looks as the data and analyzes the situation as it is rather than hope for a miracle. Odd enough, he also has some underhanded thoughts. During the Singularity of Septem, he suggests Mashu to record the events happening, thinking he can possibly make it an addendum to history. Such records should be classified, but his reply is that "there's no guarantee the attack on Chaldea will be reversed, so his paycheck is at risk". It goes to show sometimes an idiot is not an actual idiot. He knows how to methodically plan ahead. His general attitude doesn't paint him as an intellectual, but he very much is a scholar (and fanboy) of history, too. His views on reality don't only apply to situations, but also people. There's no hesitation in calling Lev's act the biggest betrayal to humanity. He also has mentioned that while Olga isn't a bad person, he wouldn't say she isn't a good person, either. However, he thinks she can be trusted.

It's worth to note that Romani's pessimism stems from his time as King Solomon. As King Solomon, he feels that he had no will of his own. He is a messenger of God, a vessel given a role, and only follows a plan. With so many expectations and achievements to live up to, it is hard to truly enjoy life at all. He seldom saw the positive light in anyone or anything. You can even say that King Solomon is an apathetic figure, a puppet for a master. Still, he has a wish to live freely as a normal man. As a normal man, he becomes capable of not only accepting people for their faults, but also their strengths.

Romani has a contrast of views due to his newly rekindled sentimentality. Despite grim predicaments and harsh times, he's able to keep his head high and find some silver lining despite his negative disposition. It also doesn't deter him, either. While he's always been called unreliable to the point that it's a meme, he's actually diligent and loyal. He works hard (with breaks in between) and sticks with our Heroes even when Chaldea's numbers lower to a handful. Unfortunately, with his meticulous ways, he gets performance anxiety and tends to make mistakes once in a while. It's not always shown, but it is referenced in one of his skill descriptions called High-Speed Incantation. He just messes up from being nervous sometimes. Not even the chosen one is born without faults.

In the end, Romani is a simple man with a complicated past. All he wants is to live a normal life--he asks for freedom, away from the burdens of humanity weighing on his shoulders, but he finds himself back where he was. There's still a difference, he truly feels he's doing this out of his own free will. There's this passion, this volition, that drives him on. That, and the people that inhabit the earth, are what matter most to him.

Romani, as how he is in his world, is human with no magic. However, as his original self, he has the power of a great Caster. Casters are not known for their combat ability, but their sorcery. If we are to look at his Servant stats, his strength is definitely not impressing.

There's not much detail about his skills, but he has a couple:

• Territory Creation makes a workshop in an area; it increases one's own magical aptitude within a radius, but it's generally a space for a magus to conduct research and experiments. He's capable of making a "temple", a tier stronger than a normal workshop.
• Item Construction lets him conjures potions and elixirs, though nothing as strong as a potion of immortality like Medea or the philosopher's stone like Paracelsus.
• High-Speed Incantation is a common skill among Casters, including Solomon. It is the knowledge and expertise in reciting chants and spells at high-speed, letting them cast spells a faster and more efficient than others. While he's adept and known as the King of Magic, it's ranked lower than expected due to his slip-ups.
• A core part of his history and life is being able to hear the voice of God. It is what it sounds like, really.
• He is also gifted with clairvoyance, specifically precognition, which lets him see into the past and the future voluntarily.

At least as a human, he's adept with technology. Time and time again, he works with data at Chaldea despite being head of the health operations (of course not by choice). As an example, he has set up an AI of his favorite idol Magi Mari to periodically update since the world is in turmoil outside Chaldea. He also works as their support, surveying weird anomalies and delivering important information to our Heroes of Grand Order.

Yeah, he's just a nerd that knows a lot about history, magecraft though incapable of doing it now, and working with technology to some extent. You won't find him asking questions on how to use Facebook, at least.