Recently introduced this rooster and two hens to my flock and noticed my roosters had some dark areas the next day. Could the hens have pecked at it or stress from the introduction to the flock? Illness?
Agreed peck wounds. I would say they are showing him his place in the pecking order not so much stress. Adult hens will boss around new roosters (especially younger roosters) to show them how to be respectful.
Peck wounds to wattles and combs look worse than they are. Those are blood-rich tissues, so they can bleed quite a bit, scab over, and be nothing to worry about.