Just had to play 8 skirmishes to get 5 executions for your Skirmish Executioner daily order. Don't get me wrong, the Centurion's executions are beautiful and cool as fawk, but they're so slow and flashy that actually getting to pull them off in any mode other than duels and maybe brawl or elimination if you're quick enough (not likely with how weak the Centurion is and how long it takes to chip away at your opponents health with this punk) is painfully difficult. 8 Skirmishes to get 5 executions, because every time I'm trying to execute my opponent the slow animation is interrupted by other opponents who had plenty of time to come to the rescue, stupid allies spamming attacks or AOEs knocking me out of the animation, or guardbreak happy captains who had time to jog from wherever they were standing to where I'm fighting. This is completely unacceptable. Give him a fast "kill them and move on" execution like the Orochi's From Above, or at least make his executions uninterruptible. You've already nerfed him into the ground in response to crybaby whiners. He's so weak that even his battles against the glass cannon shinobi are extended affairs, his light attack not even hitting for a 4th of the shinobi's health blocks and heavies barely hitting for half of a health block (this is with heroic gear weapons all increasing his attack power by 12% and defense penetration at 16.5%). If you've actually managed to chip away at your opponents without getting massacred you deserve the execution.
I can agree that some of the Centurions executions are slow, but he is a gladiator inspired character and the gladiators were showmen. Sure, they could be faster and could be more less of a "show" and more of a quick kill. That i can agree on but the uninteruptable part no, if one hero should get it, all should get it. Also something that bothers me is that the execution "Pollice Verso" has the symbols for "Spare" and "Kill" vrong. If i remember my history correctly, the "Thumbs Up" was for "Kill and the "Thumbs Down" was for "Spare" so that part was more or less the first thing i noticed and bothered me.
And one or two thing i think was more of common executions in the arenas was something like thrusting the sword at the side of the neck, throu the collarbone down to the heart whilst having the opponent on their knees (like the Raiders "Neckbreaker" and "Headcrack") or thrust the sword between the shoulderblades whilst having them on all four (like the Lawbringers "The Stomp"). Not really sure about any other common executions but all should remember that the gladiator fights were more for entertainment and show of skill rather than a fight to the death.