Ok so you want to make a group about the 7 swordsmen. Good so far.
You want the swordsmen to already be sannin or kage rank, meaning that we are talking for specific people who are already allowed: custom jutsus, custom element #1, custom element # 2, co-creation of custom elements (2 of them), all jutsus of all known elements, advanced KG abilities, at least one specialty for each one of you guys (like Roku's music arts and Izuna's amazing sealing customs etc), taijutsu, fuuinjutsu, kinjutsu, summonings and if i forget something you add it here.
The only thing you guys don't actually have is medjutsus and that's cause Nexus and I keep those a secret for now even for the med students.
So why the heck would you need a special custom sword? to get even more powers in the battle arena? a group of already too strong people?
Just stop for a second and think about it. You are talking about super "overpowerness" here and I don't agree with this.
Cause we are talking about specific people who are already incredibly strong just getting...even more incredibly strong.
Also there are no rules about custom swords and i am not up for making any of those nor approve a sword that will be made to either shoot chakra out, or smell the opponents blood or just make the opponent pee on himself.
The second No is mine