I've tried to beat the boss without the stone, and since I've started again and received the "3 stones in one" I fought him once, and I was forced to reset because with the stone I entered spirit form and when the boss hitbox colided with me I was teleported to the forest to the right of the village inside dirt, I was able to move but not to change rooms, I'll probably play it 50 times before cheat engine it, so If this bug is always on or if I find any other bug I'll let you know. I also love the fact that you put like 2 firestones and 4 fireplaces (or somethong like that) so I need to choose carefully which spawns I create, but the "keep inventory after death" is perfect, I feel the urge to explore more and more because exploration and risks are rewarded, but I wouldn't mind if in future versions this feature is removed, I feel like there is no punishment besides walking and revisiting places and for now this seems to be one of few games that uses this "no punishment" in a positive way withouth the feeling of cheating, Im really impressed and now I'm even more motivated to create my own game (even if takes years to come to an enjoyable level, I'm still learning how to use Godot)
Those stones shouldn't be doing anything at all, their usage hasn't been implemented yet =p
It is however very alarming that the boss is teleporting you to the village... I have no damn clue how that could be happening, if you could give me more info about that, I would be very thankful. Is this a once off thing? Has this happened anywhere else? Did it happen on your previous run (the stone won't be affecting it). Did this glitch happen every time that the boss hit you, or just one, very peculiar time? Did the game teleport you instantly, or were you flung there by some overwhelming force that sent you flying through the level geometry? What was going on with the morph? It sounds like you were forced to morph, but that shouldn't be happening...
I've fought this boss 10~15 times in my first play, but with 4 energy bars collected, no glitch, I'll play it again and check if it's a "5 energy stones" glitch, and I was tp before the entrance, but I was below ground collision box and it counted as defeating the boss, I've received the congrats(with my little knowledge of coding) perhaps the bug is that if one overlaps the other theres a bug, but I'll test again in the same conditions (before talking to the first villager illusion (I've never made until the second illusion because I had to shut down the pc at the only moment I reached 2nd illusion chat)