ninjas by far.
An experienced gladiator can defeat a ninja, but not easily. The techniques of a ninja warrior are based on stealth and quickness of attack. In an arena, the ninja would lose to a seasoned gladiatorial fighter.A well-equipped ninja, weapons-wise, however, would fair better in a dark alley, enclosed spaces or a forest no matter how much armor the gladiator is wearing.
A sniper would win cause he could see the ninja way before the ninja even knew were he was.
To the death or until one combatant surrendered. But remember, they did not always fight to the death, more times than not a gladiator would get a "misio" which could be likened to a pass. He'd get off with his life, but would not get paid for his combat for that day.
In Latin. I'm or I am a gladiator would be "sum gladiator".
In theory yes. But you would not get an aristocrat being a gladiator they woud host the events. Normally they were slaves and if they did well they may be freed. Contrary to popular belief not all Gladiator fights were to the death. One must consider that gladiators cost money and time to train so sometimes they may fight to the death other times not.
Samurai is the first one eliminated. Shaolin monk would be an even match for a ninja, but would prevail due to the fact that Shaolin monks take a lot of damage without feeling pain.
The hulk
probably scorpion
Rambo
Black bear
Peter
Gladiator all day niqqa