Let's talk about pre pull Hyoton and ninjitsu combos

[Gemina]

There's no need to change anything, high-end duties always have countdowns and anything that isn't a high-end duty you can pop Huton extremely early or just Huraijin and it won't make any difference.

I don't necessarily disagree with this, but I also don't excuse subpar openers because, "it doesn't make a difference." It's also one of the reasons why I frown upon abilities like Huraijin in general because such abilities encourage bad play. The moment such things are acceptable, then arguments involving ice mages, heals-only healers, or not using AoE on trash pulls go out the window.

As for removing TCJ, Meisui and Kassatu, that's kind of half of the ninja burst gone without any suggestion on how you would replace them, ninjutsu combos doesn't really explain much and it sounds like it would only end up hurting ninja by limiting their oGCD priority choice usage and forcing them to become static with little choice.

Meisui exists because of TCJ. Hence, why it is gained @lv72. With TCJ gone and the implementation of ninjitsu combos, the ability would no longer dispel Suiton and just grant the Ninki and increased potency to Bhavacakra as a follow up to Suiton. Kassatsu in its current form will no longer be needed with ninjitsu combos because you will always have access to Goka and Hyosho as follow ups to Katon and Hyoton respectively. However, I think Kassatsu can be a passive buff granted through use of certain skills in order to increase the damage of Hyoton and Hyosho so they get priority over Raiton during burst windows. The potency added from Kassatsu to Goka can simply be baked in. NIN is already static, there is very little variation to their oGCD priority. Plus Kassatsu already gives NIN a psuedo third mudra charge since NIN can utilize ninjitsu without consuming the resource. Pre-pull Huton also serves as a third mudra charge, which is what lead me to that suggestion.

The 3rd mudra charge would most likely just end up being saved for more Raitons vs using it on Huton would be a dps loss no matter what, and if you remove Hide reset then ninjas are gonna be asking for 20 sec countdowns to Huton prepull to keep their 3rd charge.

Mudra no longer being available outside combat fixes this. Right now, NIN has access to two ninjitsu outside combat that can be executed: Huton and Doton. The latter has already been rendered useless for the exact reason you mentioned here. I think it might be a good idea to prepare mentally for this change because I believe it to be very possible. If Huraijin is also pruned, then it will force NIN to open with Huton, and that's why I suggested to add damage to it.