• Mammon is the second eldest and second most powerful demon lord, yet he rarely shows this power via strength or display.
• Mammon is known to be the fastest of the brothers, boasting that none of the others can catch him - confirmed by Beel.
• Levi reveals that Mammon easily overpowered him when he attempted to get his figure back, yet Mammon also allows Satan and Asmo to string him up instead of fighting back (though quite possibly he was fishing for MC's help 👀)
• Mammon prefers to talk his way out of situations, and he mostly ends up in trouble due to his stealing and impulsive actions - not by using his demonic powers.
• Mammon is insulted relentlessly by all of his brothers, punched multiple times, punished by Lucifer and called every name under the sun (Beel is mostly an exception).
• This does hurt Mammon though, as he expresses confusion when MC is nice to him, stating MC is the only person who isn't mean to him.
• Yet the other brothers rarely insult each other beyond mild teasing, and if an argument was to break out it's hinted that the damage would be immense. But Mammon never escalates the situation by transforming into demon form.
• Mammon often makes amends for his actions - not wanting to be parted from MC after ditching them once, replacing stolen items - and sticks up for others - defending Belphie against Lucifer, and helping MC.
• His brothers often forget how powerful Mammon is, because he has such control over his powers.
• But Mammon demonstrates his true power by how he doesn't use it, no matter how emotional or provoked he is. He never, ever, loses control.
• Mammon is the only brother who never seriously threatens MC nor attempts to use his powers on them.
• Mammon is the only brother who never loses control and transforms into demon form despite being the most provoked, punched, and punished.
• Lucifer, the most powerful brother, transforms multiple times and threatens MC.
• Lucifer puts MC into Mammon's care precisely because Mammon is the only brother who can be 100% trusted not to harm MC.
• Mammon is also very honest with his thoughts and feelings from the get go. Aside from his tsundere ways, he has no problem spilling his guts to MC - someone he knows won't use it as ammunition against him.
• Mammon turns down the rulership of the world, despite being the literal Avatar of Greed, stating he only wants MC.
• I reckon the one thing that would make him angry - though I think he'd still choose to transform - is if anyone made a real threat against MC after a romanced Mammon admits to himself he loves them.
(Obey Me! Theories Masterpost)