(covers information from several alternate timelines)
When the Narada was thrown back in time to 2233, creating an alternate reality, the ship attacked the USS Kelvin. Nero then had Ayel contact the Kelvin and tell its commanding officer, Richard Robau, to board a shuttlecraft and join them on the Narada, ostensibly to negotiate for a for a cease fire. When Robau was brought on board, Ayel spoke for Nero, questioning Robau as to the whereabouts of Ambassador Spock and his ship. When Robau answered that he was unfamiliar with Spock, Ayel queried the stardate. The response spurred Nero to kill Robau and continue attacking the Kelvin.
Twenty five years later, in 2258 of a now-altered timeline, Ayel assisted Nero in the capture of Spock and his ship, and in the destruction of Vulcan. Nero had Ayel prepare the red matter from Spock's ship which was used to create an artificial black hole in the center of Vulcan, devouring the planet and killing the majority of the Vulcan race. When James Kirk and Spock invaded the Narada as it attacked Earth, Ayel took down Kirk with a surprise attack, allowing Nero to assault and nearly kill Kirk. Upon hearing the news that Spock's ship had been taken and the Narada's drilling rig had been destroyed, Nero left Kirk to Ayel. While grabbing Kirk by the neck, Ayel remarked that he was surprised at how weak Humans were. Unfortunately for him, he was too busy gloating to notice that his "victim" had been able to grab hold of his disruptor; when he offered Kirk his last words, Kirk chose "I got your gun!" and promptly shot him. Ayel's body fell from the platform he was standing on and dropped into the depths of the Narada. (Star Trek)
Ayel was portrayed by Clifton Collins, Jr..
In an early draft of the script, Ayel protests to Nero about destroying Earth, explaining their revenge was achieved when they destroyed Vulcan. Nero understands Ayel's concerns and his crew's desire to return to Romulus, but wants all involved in the destruction of their homeworld punished. When Ayel threatens mutiny, Nero kills him.  The novelization of the film does in fact use this scene. In the Star Trek: Nero comic series, Ayel makes this argument during the time between the destruction of the Kelvin and the Klingon capture of the Narada, but rather than execute him, Nero is able to convince Ayel of the necessity of their quest.
There was a tradition on Romulus that when a loved one died you would paint your grief upon your skin. Ancient symbols of love and loss. In time the paint would fade, and with it the period of mourning. Life would go on. We paint these symbols on our skin now. But we burn them deep. So that they will never fade. Because life does not go on. We died with our friends. We died with our families. We died with Romulus. And all that is left is revenge.