Aight so I wanna talk about my Mr, Mr, and Dr AU a liiiiiittle bit
I'm not sure if I've ever stated this, but I've always seen Mr. L as a weird brainwashed/inner desire mix, and I kept that in mind when I made Mr. M and Dr. L (beta designs below)
Something to note: Mr. L, Mr. M, and Dr. L do not know each other: they've never met a Mario, Luigi, or Lexi in their lives. This is a mix of how they'd turn out without them, + more evil brainwashing mixed in
Mr. M grew up always being the best at anything he tried. Sports, schoolwork, hobbies, really anything. As a result, he's now lazy. He's still pretty good at things, but he doesn't put too much effort. Often times he opts to fight the enemy later, lazing about and binging different food. He's smart and powerful, but held back with his laziness. However, he tends to put it more effort if someone is ignoring him, or isn't impressed with him. He's desperate for attention and validation. Without it, he becomes panicked.
Dr. L is actually very different from Mr. M and L. She traveled Kingdom to Kingdom, city to city, town to town, desperately trying to find some place that'd accept her. No one did, and after a long string of people calling her awful things, she just gave up and became the "Monster" everyone told her she was. She's a sad villain, constantly making jabs at others, even trying to ruin people's happy moments. No one loves or cares about her, why should she care about anyone else? Or really, why do they get the love she's been able to get for years? She's often annoyed, her voice sounding tired. She's also often down on herself, think almost like a certain hope boy from Dingo Rango
(if you want to send asks about this please do! I love to infodump)