immortal, there's a far cry between a common thug and Snake Eyes. He wouldn't win based solely on his willingness to kill; he would win on his fighting ability, speed, and training, as well as his tactics. Bruce Wayne was a whiny spoiled rich kid crying about his parents before he was trained by the supposed "ninjas" in the "League" (which isn't even a traditional "ninja clan", but a criminal group that more resembles Chinese or Tibetan fighting styles than anything else - there was a great article on that in IKF a few years back), Snake was killing VC with his spec forces LRRP in the nastiest bush in Nam, before he joined Stormshadow in the established ninja clan. Also, he was trained by two hardened martial arts/ninjitsu masters...not some chump mercenary. As to being able to use his terrain and surroundings, as well as ninja-inspired gadgets? like Bane said, "Oh you think the darkness is your ally?" Also, Snake and Stormshadow were the original ninjas before Frank Miller rewrote every character as a ninja in the mid 80s (please see Wolverine, Batman, and Daredevil). Being fighting machines is what they were, the ninja background was added for flavor to characters who already had a niche (gadgets, healung and claws, radarsight...) Please find me a batman origin story where he's a ninja bdass before the mid eighties. In short, these popular characters ripped off a piece ofthe old Lary Hama Marvel original ninjas. I love batman, but I'm sorry, he would get trounced by real martial artists (with uzis).
I hate posts like this. I really do. I mean, it's all so wrong. A bunch of opinionated, biased garbage that's nowhere near being a concise argument - it's complaining and citing things that don't even matter. If a "Whiny spoiled rich kid crying about his parents" is all Batman is to you, maybe you shouldn't post things in his threads before doing proper research. Plus, you're referencing Nolan's Batman, who isn't even being used here. I'm pretty sure the comic book Batman has had training than Snake Eyes or Storm Shadow - He's a master of 127 different martial arts styles.
Anyways, I don't know who to root for here. This could really go either way. Snake Eyes and Batman have very similar physical attributes, but I believe Bruce to be more skilled. Plus, if he has his standard gear, he could use the element of surprise on Snake Eyes and KO him with Tear Gas or whatever midway through the fight. But on the other hand, Snake Eyes could dodge that. Hmmm, hard battle.