So... i put on all my ninjas on 8gates ninjutsu, attack, defence, resistence, life, crit, injury and dmg reduction runes. Ik initiative is what u need but dont feel like 8 gates is the place to get it.

This is how i build Eight inner gates on my pos 1: (All 5 substats: Init, injury, crit, controll and combo + Att, nin and life) Maybe dmg reduction could be useful, not tested yet.

In my opinion, u should put the 5 main stats e.g. (life, attack, defense, ninjutsu, resistance) altough it also depends on which ninja u are using. For example im using Edo-Release Madara as my pos1 so i completely remove resistance since he is immune to nin dmg. But my best advice is that you put all the core stats paired with ini, critical and injury, if you remove lets say life, you should put control instead of it. You really dont need nin and tai *ion over these mentioned above i feel like.

I agree with this. Actually this is how I manage mine. Ino GNW do not have damage standard, the only thing that ties her to tai is her Mys, so for her I think I would not choose attack or even combo actually. So basically it is about setting up the right runes for specific ninjas you want in your lineup. Tho I think filling up the basic attributes heavily influence the increase in one's battlepower (not so sure). Ofc one's judgement is what really matters, all up to you!

But others choose to take this opportunity to up non-primary/non-secondary skills. As I quote from Jiburiru's old comment: "Taijutsu Pen is the Taijutsu damage that ignores defense. While Ninjutsu Pen is the Ninjutsu damage that ignores resistance. Keep in mind that this value is also affected by the Damage Reduction stat."

Just like others want more elemnetal resistance in ninja tools (I am one of those hehe) rather than primary stats. You may lose overall-power but it can be effective to heavy elemantal damage dealer, mostly the well known blitz and many more.

For the combo, I think if the skill is "fixed" to cause combo then better find some other attributes to up. But for non-fixed, I think adding combo will help alot since the opponent's combo stats will determine the success when the execution takes place.

Definitely put injury instead 1 of those. Will boost crit dmg significantly.

Same for me, 5main stats then crit+injury and initiative for pos1 ninja. From my testing nin/tai pen gives a lot of power but does close to nothing in reality. As for other positions can drop initiative for control or dmg reduction that seems to work better than pens