I’m sorry but I think Eggman being pure evil and a sadist actively goes against his character:
He is an Egotistical Tyrant who wants to build a Theme Park and rule over people to make them recognize his genius because he never got that during his childhood due to living in the shadow of his late cousin and feeling neglected by his family. That is Eggman to me.
And that's how i know you didn't play the games. Or else you would renember that Eggman, who is constantly shown to gloat about being a evil scientist, was planning to use Perfect Chaos to destroy Station Square, causing the deaths of millions of people in the process to build his Eggmanland and even had a nuclear bomb as his backup plan in case the beast was defeated or during SA2, where he was feeling pleasure in having to kill Tails right after he presumably killed Sonic by dropping him off in space just to mention a few examples. This was always Eggman's character in the games. A mad scientist and eccentric sadist who wants to take over the world for his completely evil and selfish desires. Eggman was always pure evil at heart.
