I LOVE the parallels between Gerald and Eggman in Sonic 3. ESPECIALLY with how they treat Shadow/Stone (their respective henchman/helper).
Eggman's BLATANTLY honest with Stone, and certainly blunt, but he actually DOES care about him. In Sonic 1, he looks down on Stone, calling him a sycophant and stupid ("Way to go, you got that one"). In Sonic 2, he doesn't seem to hold Stone in a higher regard, saying that he and Knuckles should ditch him, and leave him at the Mean Bean. While Stone's completely loyal to him, and it's clear that he cares about Eggman, it's only in Sonic 3 when Eggman actually realizes that Stone IS the only person who ever cared for him.
Meanwhile, Gerald's manipulative. He seems to talk down to Shadow, primarily ordering him around and only bothering to keep him out of harms way during the London heist, BEFORE he has access to the Eclipse Canon. He actively preys on Shadow's grief, telling him that he needs to remember that Maria was taken from them, and that humanity deserves to be destroyed. Gerald doesn't even bother with correcting Eggman when he calls Shadow a "Thermonuclear gerbil". And when Gerald sees that Shadow is now working with Sonic, he says "I see you chosen betrayal. And you were once so useful to me."
Gerald was (likely) only using Shadow as a tool, something he could discard when it no longer had a purpose. But Eggman WANTED to keep Stone around. He IS the reason that Eggman tried to save the world. To Eggman, Stone was MORE than a henchman and sychophant. He was a sychofriend.