You can consider replacing the essence of this system with ice light

So in the final stages of development, he managed to get rid of some bugs
With over 300 bytes of space left, he finally managed to sneak Fantasy into the game. Without the president's approval, Fantasy is not part of the official compilation of 150 Pokémon and will only be found under very special conditions. And because the bug was not cleared up, it is only possible to find it in some of the cassettes, most of which are not available in any way.