Hmm… I’m not sure that’s a huge limitation tbh. Yes, Initiative becomes important, but all the fights we’ve had so far I think there would be time to cast out of melee and then get in there.
That said, I could happily be wrong. It certainly looks like you’ve carefully considered the theory of balancing it as a spell. My feeling is that only by some extensive playtesting could we find out if it is overpowered.
You asked about the other abilities:
Soul Dance - That’s fine, it’s the Bladedancer skill by another name, and fits the idiom of the character. It’s a good fit.
Soul Shield - In my game at the moment (All 1st level characters), the ACs top out at 5. No-one has Plate, yet, so perhaps that’s factor. I don’t see anything fundamentally problematic with this, but it is, essentially, permanent unless dispelled. I’d reduce the duration to force the player to make a tactical choice about using it - maybe 1 Turn duration. It kinda feels like free Plate+Shield at 2nd level at the moment. Whilst Dispel is a threat, I don’t see it as a common one unless it’s a common thing in your campaign world. As with Soul Blade, I’d probably tweak it down a bit, but the concept is great.
Meditative Focus - Really like this. Supercharge yourself for a Turn. 1/day/level. top.
Blade Burst - I love this. Though you need to add the radius of effect onto the description of the spell. I assume it’s 30’. Visually, I see it as similar to the scatter effect of Senbonzakura, the special sword of Byakuya Kuchiki from the Bleach Anime (If you don’t know what I’m talking about, his katana blade scatters into razor sharp peach blossoms.) Love the idea. I assume that this will also terminate any Soul Blade spell that’s ongoing.
I’d love to drop where it appears in the level progression so the Soul Knife can get some earlier use of it, and not at it’s maximum damage potential. As soon as the character gets it, it’s at full power, which feels like a missed opportunity.
Name level - I kinda feel like ‘Fortress’ isn’t evocative enough for the class to do it justice. I want it to evoke something to do with the soul, their state of enlightenment, and the intense focus they have to have to use their skills. Fortress feels more warlordy than Soul Knifey. Fortress-Monastery is marginally better, but I think there will be better options. Pagoda? Temple? Dunno, sorry.
As far as the new spells go, they look fine to me! Greater blade burst is nasty, and the others are nice utilitarian spells reskinned for flavour. I totally approve of reskinning and renaming spells for flavour!