The Superhero Database Classification number, or SHDB Class, is a number that represents the overall 'power' of a character. All traits of a character are used for calculating the Classification.
What it DOESN'T mean
This doesn't mean that a higher class would always beat a lower class character. But the bigger the difference in Class is, the more obvious it is who'll win in a fight.
How is this calculated
( INT^1.3 + (STR*0.5 )^2 + (SPE*0.5)^2 + DUR^1.6 + (POW + (SPS*SPL))^2 + COM^1.8 ) ^ TIER
Super Power Score and Level
Every Super Power has a score (SPS) that is used to calculate the Class. Each Super Power also has 3 levels (SPL). The level is set when connecting that Super Power to a character. The level determines the final score, of the Super Power, being used in the calculation.
So he just need to shrink the sword [but without store] (with Sukuna-hikona) that will disable gorr sword (the sword being shrunk will become useless). So That will make Gorr unarmed to fight against him and unable to kill him.
This isn't like sending the sword into the microverse, but just making the sword into a very small miniature... it's like when Ant-Man shrinks his car or his lab. (Gorr sword will be useless)