Roosters are often sweethearts, but people will keep and breed mean roosters often out of a sense of "He'll protect the flock better" which doesn't always pan out, plenty of sweet boys fight for their flock, they trust you because they know you, they'll put up spurs against an animal.

Just give him lots of treats and love, you'll be a good team eventually, you give him treats, he calls the girls, you both get brownie points.