Most verbs in English have a predictable past-tense marker: the -ed ending. A few verbs, the irregular verbs, don't have that marker. For instance, 'Go' becomes 'Went', such as, 'I'm going to the park' vs 'I went to the park'. A few - cast, cut, hit, hurt, put, quit, set, split, and spread - are the same in both the present and the past tense. There seems to be no question for eight of these words but for 'cast', people are now using 'casted' for the past tense.
Two or three years ago, Tim Pool stopped himself mid-sentence on his show and wavered between 'cast' and 'casted', finally opting for 'casted' since he didn't know. He's in his thirties. He might be a high-school drop-out, but he's still educated, and 'cast' vs 'casted' is taught, or was taught, in elementary school. How did he not know? How does Asmongold not know? People of that age group and younger seem to be completely ignorant of their own language. 'Cast' is the past tense of 'cast'.
My older daughter, in her 40s, said she could possibly see a case for 'casted' when saying that someone had a cast put on. Maybe. If I squint. 'I was casted' or 'They casted me' might fly, but most people say, 'I got a cast' or 'they put a cast on' when talking about their broken bones. This would be different because it's creating a new verb from a noun, the cast, plaster or inflatable, in question. But even when talking about a 'casting' as in a foundry, the mold was still cast, not casted. So, if you squint, 'casted' could be a thing medically, but only if you squint really hard.