Cell Max embodies the pinnacle and perfected version of Cell.

In the movie Dragon Ball Super: Super Hero, fans are introduced to a new antagonist named Cell Max, a truly ferocious fighting machine.
Cell Max is so ruthless that Gohan had to unleash his full hidden potential to defeat him. At this point, Beast form is Gohan's ultimate power. Even Orange Piccolo with all his might couldn't accomplish this.
How powerful is Cell Max?

Cell Max is an apex monster. Despite not being at 100% full power, he surpasses most antagonists we've seen in the series so far. Cell Max has faced multiple Z warriors simultaneously, dominating them all.
Despite appearing stronger than Orange Piccolo at times, Cell Max suddenly gets defeated by characters like Krillin and Android 18, leaving viewers perplexed. It's baffling to witness someone who nearly vanquished Piccolo perform poorly against significantly weaker opponents.
Despite these inconsistencies, Cell Max still leaves a significant impression on readers. Many believe he's on par with Jiren in terms of strength.
Is Perfect Cell Max's power overwhelming for Gohan Beast?

People speculate that if Cell Max appeared in his perfect form, he could be as strong as or even stronger than Black Frieza. However, this is merely fan conjecture until he officially debuts in the series.
Many anticipate that Perfect Cell Max could pose a major threat because he evokes memories of Imperfect Cell before he absorbed Android 18. Do you recall how Cell transformed afterward? Super Vegeta vastly surpassed Imperfect Cell, but only Super Saiyan 2 Gohan could defeat Perfect Cell.

Therefore, if we apply this logic to Cell Max and assume he possesses similar strength, even Gohan Beast wouldn't stand a chance against the antagonist.
It's essential to remember that Cell Max is a new and improved variant of Cell, created by Dr. Hedo, Dr. Gero's grandson. Despite being an imperfect form due to flaws in the mind control program, Cell Max is much stronger than Cell. This implies that Cell Max is an uncontrollable beast compared to the previously intelligent Cell.
Therefore, what Cell Max lacks is the mental control for the Red Ribbon Army to command him. So, in reality, Cell Max couldn't become any stronger in the battle that Gohan Beast defeated him.
But let's imagine if Cell Max could become even more powerful. The Z warriors would have to join forces to stop him. However, there's no guarantee they could accomplish that.
In conclusion, if Perfect Cell Max existed, he would undoubtedly be on par with Black Frieza, or even stronger. Some argue that even the ordinary fusion of Goku and Vegeta wouldn't be sufficient to defeat him. Perhaps the two Saiyan warriors would have to merge into their ultimate form to create the most potent warrior in the multiverse capable of overpowering Cell Max.