If he's going to be nothing more than an impediment, I'd cut him. But if he stays and he's done well, he will lend a great amount to the story and make it more than just a revenge drama. He could well be a useful helper as well as the conscience of the story instead of (or as well as) an impediment that needs to be rescued. If I remember rightly, there's an old film about a deadly samurai who has to protect a small child (in a pram?). Something like that was done in The Walking Dead and the computer game The Last of Us.
But, if you can't make it work, or it isn't the story you want to tell, I'd suggest cutting him, as he'll only be a nuisance otherwise (depending on the circumstances of the story).