Based on what exactly? He doesn't have feats remotely on their level.
Plus, Zetsu Orochimaru is like completely featless.
Zetsu Orochimaru can hold Tobirama who was stronger than Pre Zetsu Orochimaru who scaled to regular Jiraiya and Tsunade.
its literally a shitton of chakra being released from a seal. makes no sense for it to NOT be an amp, considering the fact that it works the same way as kurama's chakra leaking from naruto's seal and amping him lol
It's not a shit ton of chakra being released. Whenever they get bruised, the chakra is being used to fix it. Whenever they're tired, the chakra is being used to energize them.
It is in no way, shape, or form the same as Kurama's chakra amping Naruto. Kurama's chakra has higher potency. It's denser and stronger. A little bit of Kurama's chakra can throw you 2 tiers above.
The chakra from the seal is regular chakra that has just been stored over time and is used to heal. Nothing says, shows, or proves that they get stronger.
Doesn't the Strength of a Hundred technique give the user a power-up? What else would the Strength of a Hundred technique do?
Ninja Art Creation Rebirth — Strength of a Hundred Technique, or Byakugou as the Vs Battle Wiki says, is a combination of Creation Rebirth and Strength of a Hundred Seal.
Creation Rebirth by itself, via Tsunade's words, uses large amounts of chakra to split cells for rapid regeneration. You can check more about it
here (it's databook translations). Strength of a Hundred Seal is just a huge amount of chakra, so she can heal for longer periods of time.
Not once on canon has it been shown, proven, or even implied to be a boost. Sakura's only feat w/ it on is punching an average sized Juubi spawn which Base Naruto and No Sharingan Sasuke (and everybody else in base) fought with no issues.
Not all additions of chakra is a power-up, cause then we would have to say shadow clone jutsu, which splits chakra, is a handicap and makes people weaker,
yet we see Naruto who splits his chakra thousands of places doesn't get weaker at all.