since the core stone is meant to be a teaser for rogue core anyway, maybe they're just waiting and going to have it in that game's OST too. would be a weird way of going about it, but, wouldn't surprise me :P

I think they just never got around to adding it to the OST or maybe forgot to add it, one of the two.

tbh i just used what was in the official OST, and the core stone theme isn't there yet, so it got missed. thanks for calling attention to it though! expect an update soon.

Could you add this into the combat tracks? I can understand that this might have been missed due to the rarity surrounding the item needed for this.
https://youtu.be/gkn2XwpM8GM