The puzzles being called "Levels" for that reason makes sense, and I do like the distinction. The easier ones feel to me like a crash course tutorial in how a certain piece works, and I'm all for that.
Also, I really like the Promote idea for Tokinko! If it didn't cost too much blood, then her strategy would be to get some blood early, then set up strategically and think ahead. Any of her pieces could become something more dangerous at a moment's notice, so an opponent would need to be thinking of how to defend against it currently and in the near future. I'd be interested in seeing how that works out in-game.