As The Demon Hawk said, Momoshiki's power fluctuates thus any ranking we give him isn't his true ranking. But:
-Base Momoshiki w/ the absorption jutsu would beat any powerhouse who used chakra/Ninjutsu as their main form of attack and didn't have any excellent CQC abilities. Tbh, Momoshiki in Base himself doesn't have any excellent CQC abilities, so if he starts off with no jutsu and has to fight people like Sage Hashirama, Madara (EMS or Edo), or Gai (7G or 8G) he'd end up losing after a rather long battle. IIRC, wasn't he getting pressured by Darui and Gaara? He only briefly clashed with Sasuke, so no one bother mentioning him. :lol And he definitely isn't any kind of speedster.
-Final Form Momoshiki however is a dog at close quarters combat. So he'd rape anyone who doesn't have the ability to contend with him at the small scale level, and relied on chakra avatars or Ninjutsu as their main power. He'd stomp Hashirama, Madara (Edo, EMS), BSM Naruto, EMS Sasuke, and the like. The weakest person who can beat this form of Momoshiki would be either Dual Rinnegan SM Madara, or JJ Madara. Gai has a chance if he uses Night Guy before the golem comes out, and even then it's iffy. Momoshiki wins more times than not.
Though if we give Momoshiki everything he used in the movie, he definitely rapes anyone under JJ Madara in power, and even JJ Madara w/o Rinne Sharingan might lose. Probably not though due to CT.