Come on you guys. Sasori defeats Hebi Sasuke even.
No he doesn't. Sasori is one of the weakest Akatsuki members and one of the most overrated characters of all time on this site. Despite what happened at the end of the fight, Chiyo and Early Part 2 Sakura destroyed the Third Kazekage and got him to use 100 puppets... and destroyed all of them as well. This should tell you something. He was an interesting character, but honestly the guys' abilities are overstated and taken way too far for what they actually are.
The guy loses to everyone in the Akatsuki bar Hidan and Zetsu. Loses to everyone in the Gokage as well after reading Cyborg (Icelerate) and Ghost in the Shell's posts about Mei. Just so you know this is regardless of whether or not he starts in Hiruko/with the 3rd Kazekage.
Tsunade loses, Mei loses in an open location from the Gokage. Sasori, Orochimaru from the time, Konan, Hidan and Kakuzu lose from the Akatsuki. Non-MS Kakashi, non-SM Jiraiya and Base Gai also lose. Strongest people he probably beats.
Mei already beats Hebi Sasuke, so she wouldn't lose to a weaker version. No he loses to Orochimaru. Pretty sure that EliteKakashi and other (reputable) Kakashi fans have proved that he mid diffs Hebi Sasuke so he wouldn't lose to a weaker version either. He loses to Jiraiya since he can summon the elders even without going into sage mode.
OT: Sasori or Kakuzu.