First, I love this game, I think that you did an amazing job designing it, and probably everyone hopes that this game will have a very long lifespan, and it will be the first in the line for similar games. I don't know any other game where you have this much control over the character's every little move while attacking.

I also understand that programming in big, actual moveset changes, like the kensei's pommel strike or even something as little as a new soft feint, and you don't want to add something only to take it back after the bigger changes. However, you should still add little things more often, because characters like valk or orochi are obviously very weak, and the players maining them have to endure it for months, making them wait for one or two more may disencourage lots of people to keep playing against much stronger heroes. That way, the valk mains will either leave or change to something else.

I don't think that anyone would really mind if you would give valk heavies +10 damage, she would still be a weaker hero, but she could get a fighting chance, and when reworked, taking it back if necessary shouldn't be hard. I can't say that I understand game programming, but changing a damage number shouldn't take long. If it's too much, you can tone it down the next weak. Decreasing shugo stamina costs or increasing orochi's damage should be just that easy. Maybe taking away the feint option of the glad zone's second part (which almost always ihits anyway, it shouldn't be even safe) is a very easy thing to program, but it might be a bit different than changing a damage number.

These are just a few examples, but at least giving something little to weak characters is better than keep them waiting and hoping. I don't think that a little more stamina or damage could save otherwise weak heroes in themselves, but still better than nothing.