Coming from a Polygon interview with Michael McIntyre, gameplay director on Arkham Origins...

"Throughout the game, [players are] doing [free-flow combat], they're doing Predator [stealth combat], they're doing navigation. And we wanted to make sure that the bosses were testing that and not necessarily testing exotic skills, things that they would have to learn in the boss fight. If you don't test people, then they're never really required to go into that depth. So we wanted to kind of require them to dig a little deeper into some of these systems." - McIntyre

- once you break Deathstroke's bo and punch his mask off, he starts throwing in other attacks along with swings of his katana
- one of the attacks sends an explosive barrel hurtling toward you

"The mistakes he makes are not in the core combat or in the core gameplay mechanics. There was honestly a very short-lived debate on the team of, 'Well, it's year two — he should mess up, he should trip, he should not have Batarangs, or he should throw his Batarangs and they should miss or, you know, whatever.' And for very obvious reasons, that idea couldn't survive. You can't subscribe to the fantasy of being the Batman and trip over your cape [in] your first fight and get stabbed in the leg by a pimp." - senior producer Ben Mattes
"He doesn't stand straight up and confident like he does in the previous Arkham games. He's fists-up and ready to go; he's a lot more aggressive. He crosses certain lines, and he's learning lessons as he goes along. [...] He doesn't realize that aggression doesn't necessarily solve all problems." - McIntyre
More screens here