While their introductions were grand, these characters' performances left fans extremely dissatisfied.
1. Tobiroppo Group
Introduced as a formidable group just below the trio of King, Queen, and Jack, with impressive profiles and captain titles comparable to Lucci... However, despite the grand introduction, Tobiroppo proved almost ineffective, swiftly defeated in solo 1 vs 1 battles. The promising siblings, Ulti and Page One, were embarrassingly taken down by Big Mom, setting the stage for Usopp and Nami. X-Drake faced constant setbacks. The Tobiroppo's performance disappointed readers, introduced grandly but delivering little.

Once hailed as the crew's best marksman, Usopp's post-timeskip victories rely more on luck than the strategic combat prowess he displayed pre-timeskip. From Dressrosa onwards, Usopp's battles share a common motif: putting in maximum effort, achieving little against opponents, then winning through fortuitous events. After his incredible long-range shot to defeat Sugar in Dressrosa, Usopp hasn't had any noteworthy or decisive victories.

3. Denjiro
After concealing his identity for decades, Denjiro finally unveiled his true face before the battle. Rather than leveraging his role for strategic surprises, like assassinating Orochi or targeting Kaido's heart, Denjiro exposed himself without a clear purpose. The only noteworthy action in his Kyoushiro disguise was ambushing Sasaki, followed by inexplicably tying him to a tree. Compared to his fellow infiltrator Kanjuro, Denjiro falls short in both skill and quality.

4. Big Mom's Pirate Crew, including Big Mom
Despite being labeled as Kaido's alliance, Big Mom has significantly aided the Straw Hat crew since the story's inception. She caused chaos in Udon prison, pulled out Queen, creating an opportunity for the Straw Hats to take over the prison and escape. During the Onigashima battle, Big Mom swiftly defeated two of Kaido's strongest members, Page One and Ulti. Later, she unintentionally helped Nami enhance her powers by abandoning Zeus. Currently, her pirate crew remains idle beneath the waterfall, seemingly without a clear objective, even though Kaido's main forces have retreated, including Marco, who left the waterfall with almost no significant power to hinder their return to the island.

5. Queen
Standing at the top, Queen single-handedly contributed 50% to the alliance's victory with both ruthless and comical actions. Notably, he released the demon ice Oni virus to bolster the enemy's ranks, toyed with Chopper and Sanji, only to be effortlessly defeated by Sanji with a single hit. Excluding Big Mom and Queen from Onigashima could have concluded the battle much earlier, with the victory leaning towards Kaido's side.
Additionally, we can mention the ineffective Number group, the Gifters who squeezed the team... However, we must also empathize with Oda for the challenge of introducing too many characters in a single arc and providing them with meaningful roles, which is by no means an easy task.