Zelazny What If: Gerard as the villain in the Corwin Chronicles

Who: Gerard

And a big, powerful man regarded me from the next card. He resembled me quite strongly, save that his jaw was heavier. And I knew he was bigger than I, though slower. His strength was a thing out of legend. He wore a dressing gown of blue and gray clasped about the middle with a wide, black belt, and he stood laughing. About his neck, on a heavy cord, there hung a silver hunting horn. He wore a fringe beard and a light mustache. In his right hand he held a goblet of wine. I felt a sudden affection for him. His name then occurred to me. He was Gerard.

Why: Loyalty

 How:

 I could see Gerard as a villain out of loyalty to an individual (such as when he thrashes Corwin on Benedict’s behalf) or out of loyalty that places the ideal of Amber over the lives of the individuals.Consider what he tells Corwin in Guns of Avalon.

 "That is why, whether I sympathize with you or not, I do not recommend the present time for your efforts. The security of Amber must come before all else."

And later

 "Corwin . . . Wait. I'd like to ask you to reconsider. Do not hit Amber now. She is weak in all the wrong ways."

"I am sorry, Gerard. But I am certain I have given the matter more thought during the past five years than all the rest of you put together."

"I am sorry, too, then."

He’s slower than his mercurial siblings and more deliberate. Plodding, even. But not stupid. Recall that in the Courts of Chaos, Oberon keeps Gerard behind the defend Amber when everyone else is dispatched to the field. Gerard functions as an adversary for much of the chronicles. In some ways he’s harder to hoodwink than his smarter siblings, because he just won’t listen if he decides it’s time to pummel you. “Can’t talk now, Corwin. Bodyslamming you on some rocks now.”

He wouldn’t work well as the primary villain of the piece, because I think he’d be too easy to maneuver around but he’d make a terrifying, implacable enforcer.