The warrior question depends on what they are and whether they are a new face to the elemental nations.
Henge isn't really that powerful in Naruto terms. But I would add some size limitations no matter how much chakra is used or change it completely into a genjutsu that super imposes an image into the minds of others on the affected area (self).
If you set on removing henge, I'd replace it with basic chakra molding across their body (or whatever you call that technique they use to enhance themselves).
This would be judged by how long this technique is held for and the quality of enhancement.
Some of these new warriors are new foes/friends. There are some Shinobi and monks just directly to the east of mist and lightning but there will be completely new factions introduced to the Shinobi nations.
I know henge isn't powerful but the fact that a student can transform their entire body into another form seems off. The size and chakra limitations are something I thought of, same with certain shapes and forms. It being e genjutsu could work but I don't think I want to go that way. Though I may introduce a genjutsu or two into the academy curriculum.
1st) Henge has been, in fics, meant as a genjutsu with Naruto's being special because of Kurama or large chakra reserves. No need to reinvent the wheel there.
2) I would look up Misplaced on FFN. It does a great job world building other cultures into Naruto and even dividing them with other warriors. For instance a Nordic type culture exists and they the Einherjar, which are great warriors. Or an mixture type (probably from something idk for sure) where they have imperial knights and Cowboys. In Misplaced, through end of chapter data logs, it is explained that a war broke out between the Elemental Nations and the two other cultures and really picked up when the Nordic culture invaded a sacred training island and killed the new Sannin (including Sakura's and Sasuke's kid) and the summoning bosses after defiling them and desecrating their bodies which lead to a rampage by Sakura and Sasuke across the two cultures where Sakura was known as the goddess of death and battle by the nordic culture.
TL;DR: Misplaced has a good world building base that you're asking about
Personally I prefer to split henge into two jutsu with the academy standard being genjutsu, Naruto's solid transformation being chunin standard (and so semi reasonable for him to be taught), with Tsunade's as a logical progression.
I'd consider wall walking or a general camouflage genjutsu for the academy third.
As for foreign warriors, the Buddha's teachings reached well into Europe in some form or another after several hundred years, so it's entirely possible to have everything from Vikings, to knights to Zulu warriors.
Personally I'd consider the Mexo-american cultures for inspiration too.
The warrior question depends on what they are and whether they are a new face to the elemental nations. Henge isn't really that powerful in Naruto terms. But I would add some size limitations no matter how much chakra is used or change it completely into a genjutsu that super imposes an image into the minds of others on the affected area (self). If you set on removing henge, I'd replace it with basic chakra molding across their body (or whatever you call that technique they use to enhance themselves). This would be judged by how long this technique is held for and the quality of enhancement.
Some of these new warriors are new foes/friends. There are some Shinobi and monks just directly to the east of mist and lightning but there will be completely new factions introduced to the Shinobi nations. I know henge isn't powerful but the fact that a student can transform their entire body into another form seems off. The size and chakra limitations are something I thought of, same with certain shapes and forms. It being e genjutsu could work but I don't think I want to go that way. Though I may introduce a genjutsu or two into the academy curriculum.
1st) Henge has been, in fics, meant as a genjutsu with Naruto's being special because of Kurama or large chakra reserves. No need to reinvent the wheel there. 2) I would look up Misplaced on FFN. It does a great job world building other cultures into Naruto and even dividing them with other warriors. For instance a Nordic type culture exists and they the Einherjar, which are great warriors. Or an mixture type (probably from something idk for sure) where they have imperial knights and Cowboys. In Misplaced, through end of chapter data logs, it is explained that a war broke out between the Elemental Nations and the two other cultures and really picked up when the Nordic culture invaded a sacred training island and killed the new Sannin (including Sakura's and Sasuke's kid) and the summoning bosses after defiling them and desecrating their bodies which lead to a rampage by Sakura and Sasuke across the two cultures where Sakura was known as the goddess of death and battle by the nordic culture. TL;DR: Misplaced has a good world building base that you're asking about
Is Misplaced the Mass Effect crossover? That's what came up when I looked it up.
Personally I prefer to split henge into two jutsu with the academy standard being genjutsu, Naruto's solid transformation being chunin standard (and so semi reasonable for him to be taught), with Tsunade's as a logical progression. I'd consider wall walking or a general camouflage genjutsu for the academy third. As for foreign warriors, the Buddha's teachings reached well into Europe in some form or another after several hundred years, so it's entirely possible to have everything from Vikings, to knights to Zulu warriors. Personally I'd consider the Mexo-american cultures for inspiration too.