Even if Alter Genesis is a TCG gimmick, it makes me think of what I could be in a video game.
Perhaps the theme is exploring the lineage of Pokemon species, and instead of mega evolution, there's Genesis evolutions that revert the Pokemon to a common "pure" beast, depending on their first type. Kind of like Primal evolutions, but all fighting types revert to Fighting Genesis Beast, Electric Genesis Beast, etc. One for each type.
