The Old Man has a different kind of presence from the rest of Sinbad's crew. He's blind, and his falcon lets the story keep him connected to events even when he stays aboard the ship. He doesn't have to be standing beside Sinbad in every confrontation to matter to what's happening.
His introduction also gives him an awareness of what is about to happen before the others understand it. He recognizes the significance of the moment when their situation begins to change, and he understands the magic involved in their captivity.
That makes him someone the captain has reason to listen to. Sinbad can deal with the immediate problem in front of him, but the Old Man brings knowledge that isn't available simply by looking at the room or drawing a sword.
He's also a good reminder that a crew like this needs different kinds of usefulness. Everyone doesn't have to win a fight in the same way. Some people help by understanding the danger before the fighting starts, or by seeing how a magical object actually works.
With all the confidence Sinbad carries around, having somebody nearby who knows more than he initially says gives their conversations another layer.
The Old Man has a different kind of presence from the rest of Sinbad's crew. He's blind, and his falcon lets the story keep him connected to events even when he stays aboard the…
· Comics / Grimm Universe