Thank youu :)) The process of making a mob depends on what you're trying to make. The soul I'm making is a snowball that displays the custom model, riding on an invisible mob. On other times I would make an armor stand or another entity to display the model get teleported to a specific mob, so that the model gets controlled by the mob. Some people would even make the AI on their own by using a bunch of complicated commands like /execute

oo nice i like it

for the mob, though, i wanna keep it as like a round square shape or a parallelogram