It's a nickname from fans for Asgore the king of underground, one of characters of popular indie video game, Undertale. According to his father-figure (like his ex-wife, Toriel. Who has mother-figure)
skibidi sigma ohio level 5 gy'att with the literal goat sauce so lookxxmax ohio rizz so muscle daddy in ohio only in ohio uncle giggled my ass when i was five
person 1: Yo are you sigma skibidi? i heard you were!
person 2: Nahh but Mathias is a lskibidi sigma ohio level 5 gy'att with the literal goat sauce so lookxxmax ohio rizz so muscle daddy in ohio only in ohio uncle giggled my ass when i was five.