The one who did the feat was Sasha lmao
Anyway, it's plain Mathematic Manipulation:
Sasha destroyed the reason and made 4-1=0 logical. Therefore, after she destroyed one of the 4 self-destruction magic, the number of self-destruction magic active was reduced to 0 (4 self-destruction magic --- 1 self-destruction magic = 0 self-destruction magic), she even says "Maximum efficiency or maximum results, no matter how correct the calculations are, just destroy them. My demon king won't allow me that 1+1 doesn't equal 3"
That's plain Mathematic Manipulation, more specifically, operation manipulation