Hi! This topic has been talked about before. Unfortunately, it is not fair for those who reached Six Paths before to not be able to participate in ranked. There are many builds out there that allows players to attain Six Path rank. I understand that it is not the easiest to find the build right for you, but with the right build and patience, it can be rewarded. One of the teams I have seen that worked really well are the Azure Fang, GNW TenTen, Mabui, and Mei team, as well as the Breeze Dancer, Regular Gaara/Kazekage Gaara, Sage Naruto (this can be replaced with other alternatives including regular Naruto), and Five Conference Temari/Pain Gakido. There are many variations of teams that can work in your favor. Both F2P and P2W alternatives are available. Even Gaara can be obtained from either Black Market or in chase missions (have seen a F2P get Gaara to four stars without recharging).

Arena usually only matches you with players with a rank similar to yours. What that means is when Arena does a soft-reset, the players who used to be Six Path would only momentarily stay at a lower rank before moving back to the rank they used to have. You will still in most cases only be fighting players with similar rank than yours.

~Jib