Not the main villain
Skinner is very well known as a villain, sometimes the secondary villain or the main villain. However, he is not a main or secondary villain because his goals aren't to train cooks and kill rats, his goals are to make his resturaunt the best in the world. what would you do if you had a rat in your'e resturaunt
On & Off Villain
He is the on & off villain of the film. one seacond he likes Lenguini and starts to care about him, but as soon as Lenguini stopps making his resturaunt (on his opinion) the best, he gets mad at him and even tries to fire him.
Not Completly Evil
He may do extreme stuff and try to kill rats but as it was told before his goals aren't to kill rats, but to make his resturaunt best in any payment.