Opulums are the 2nd non-particles in the hierarchy. They are the main component of Ijitiums and are EXTREMELY small (anything in the bottom part of class 0 and below is already extremly small though).
These “particles” don’t even really qualify to be considered as “existing”, but for whatever reason they somehow… do? There isn’t really too much information known yet about these particles due to their size, but one thing we do know about is that their scale, with many things such as dimension, are completely impossible to measure because these “particles” are somehow smaller than everything and have lower dimension than logically possible.