Fisto's proved nothing against Darksiders. AOTC Anakin has made Dooku work his hardest to defeat him, and beaten Ventress, something Fisto couldn't do (form advantage BS aside).
Anakin wins (unless Padme's just been hurt so he rushes in like a moron trying to blitz Fisto).
Anakin making Dooku work his hardest is factually incorrect, and has been retconned. Anakin by AotC performs similarly to Obi-Wan in current sources, and Fisto was easily defeating him.
I also don't think it's fair comparing Anakin's and Kit's performance to Asajj. Anakin was fighting an untrained Ventress and until he got angry, he was losing. Fisto was facing a more well-trained Ventress, who had prep and was at a form disadvantage and, from the limited detail we have of the fight, we know she only pierced his guard once after a lengthy duel.
Sounds to me like you're mixing up Canon and Legend sources here.
In Canon there is no Cestus Deception, so Fisto never proved himself superior to AOTC Kenobi.
And there's 2 sources which put AOTC Anakin above AOTC Kenobi- The AOTC Novel, and Nick Gillard. Both those sources are arguably applicable to both Canon and Legends.
Well Anakin getting angry is when he lets loose and his true power comes out. And lets face it, once he got angry he owned Ventress.
Where does Gillard say AotC Anakin > AotC Obi-Wan? Gillard claims that they're on the same level, but he also claims that Anakin has gone past Obi-Wan since AotC, which would mean Anakin hadn't surpassed him by AotC.
I'm using Composite versions, actually. Newer sources note Anakin was easily outfenced by Dooku, even sources going so far back as The New Essential Guide to Characters and old Fact Files note the same.
Not really. An enraged Anakin is just that: a rage amped Anakin. Standard Anakin, who's going to be the one facing Fisto, isn't going to perform on that level.
And he only owned her once she had one blade left. Prior to that, she actually succeeded in disarming him:
Nope, but they do close any gap between AotC Annie and Obi to the point that the two are decently close, whereas Fisto is notably above that paygrade.
Well it happened against Asajj, and against Dooku... Yeah, pretty rare. And usually, if anything, it hinders him(hindered him against Tyranus until Sheev stepped in, hindered him against Obi, hindered him against Ventress on Coruscant, etc.)
Then why did Asajj nearly decapitate him and kept scoring hits on him, while Anakin visibly struggled? And yeah, Dooku's Dun Moch did hinder Anakin:
"Dooku slipped aside from an overhand chop and sprang backward. "I sense great fear in you. You are consumed by it. Hero With No Fear, indeed. You're a fraud, Skywalker. You are nothing but a posturing child."
He pointed his lightsaber at the young Jedi like an accusing finger. "Aren't you a little old to be afraid of the dark?"
Skywalker leapt for him again, and this time Dooku met the boy's charge easily. They stood nearly toe-to-toe, blades flashing faster than the eye could see, but Skywalker had lost his edge: a simple taunt was all that had been required to shift the focus of his attention from winning the fight to controlling his own emotions. The angrier he got, the more afraid he became, and the fear fed his anger in turn; like the proverbial Corellian multipede, now that he had started thinking about what he was doing, he could no longer walk.
Dooku allowed himself to relax; he felt that spirit of playfulness coming over him again as he and Skywalker spun 'round each other in their lethal dance. Whatever fun was to be had, he should enjoy while he could."
Anakin was afraid of his anger, and Dooku pointed it out with Dun Moch, thus hindering him when he tried using it. Prior to that, Skywalker was growing stronger since he held his anger back behind walls of iron will.