How to create a good antagonist

while brainstorming the story for the RPG, I was thinking on a question i was given years ago to help with making a good antagonist.

“If you placed the player in the antagonists shoes, could he be labeled as the good guy?”

Basically, you should write the antagonist the same way that you would write the protagonist, with the paths and ideas crossing paths. The more I add story to the game the more I think I am hitting that mark:

as a synopsis:

During a major battle, you were betrayed by your leader, and possibly your best friend. blown off of a cliff and left for dead. As you were taking your final breaths, a Nomad carried you to a safe place and nursed you back to health. The nomad, who introduced himself as Susama*, tells you how you were used in the plans for the country’s merger, and that you were rumored to become more important than the kings themselves.

He convinced you to take your rightful place as leader of the realms, by taking revenge against those who conspired against you. You, in your anger, agrees with Su and begins to gather those who were exiled for disagreeing with the merger.

within a few short years you became able to rival the strength of the kings combined and you decided to enter the sacred cathedral, alone. something that no normal man can do. This act set tension across the kingdoms.

A short time later, you notice a group of Knights on patrol, some of them formerly under your command. you decided to teach them a lesson, simultaneously giving the kingdoms a warning about the consequences of betrayal. in the middle of attacking, you are interrupted. you hesitate as you stare into the eyes of a man that was once your greatest ally… and you can tell by his look that he intents to end you and your plans once and for all.

In the eyes of the antagonist, the overthrow of the government at large is more than revenge, it is him reclaiming his destiny, the born leader who is known for his quick thinking and rate of success.  During the game you will see the antagonist try to talk his way out of the fight, due to his disinterest in fighting his friend, but will fight to kill if his former colleague stays in his way. Also, this can make the protagonist look more evil, because he is getting in the way and will not back down no matter what…

I really hope that my ideas come out they way i want them to.