First of all I just want to point out that I am not trying to get the ability to use Limbo overturned in my current fight. I just actually think it could be fair. Not in Naruto but on SL.
The thing is if we followed the rules of Naruto as we know them as of the end of the series then we wouldn't have so many Rinnegan users. Only by combining the chakras of Indra and Ashura can the Rinnegan be awakened in the manga. That means that in the manga there could be at most 4-6 people with the ability to use Limbo and the ability to combat it around at any given time. And that's only with reincarnation shenanigans bringing back the past generations of Indra and Ashura reincarnations. It should naturally only be 2.
The thing is we don't do that here on SL. We stuck with it just being Uchiha DNA + Senju DNA. So an unlimited number of people can awaken the Rinnegan and gain the Six Paths Chakra required to see and damage the Limbo clones. I think it would also be logical to say that if you have Uchiha and Senju but with Sage Mode instead of Rinnegan than you could sense and damage the clones while in Sage Mode, like Naruto's Six Paths Sage Mode.
We would of course have to make hard rules about how many turns the shadows can stay out, how many you can make, and how long they remain on cooldown. Other things I am not thinking of as well I am sure.
Of course if the consensus of the community is, "Nah screw that jutsu" than it's all pretty pointless.
What do we think? Is Limbo worth saving or should it be scrapped?