First of all, thanks for your critique. I think my major mistake in this jam was trying to implement too many systems. I will try to focus more on the next one.
So, "mahou" was a poor choice made by me to refer to the game's currency. With "mahou" you're able to level up your character (equivalent to souls in Dark Souls games), thus increasing status such as HP, number of available spheres, etc. The idea of connecting spheres was made to make the turn-based combat more interesting, requiring some level of skill and a little bit of luck from the player to succeed.