kaein
A kaein is a guy who’s got the stamina of a marathon runner and the heart of a superhero, but he also has a mouth like a sailor and will curse you out if you forget his birthday.
'He’s a kaein. He’s been lifting weights since he was five and still insults me like I’m his kid.'
'He’s a kaein. I once saw him fight three guys at a pizza place just because they stole his last slice.'
'That guy is a kaein. He’s been through hell and back and still laughs at my dumb jokes.'