I have created an extensive new archetype called "Crow" Monsters. They are going to all be part of a story more complex than Gagagigo's. I would like it if I could have some additions to my booster packs and I will try and incorporate additions in the story. However, if you do put cards in the booster, you must use this fromula to determine the level of a Monster Card:
(ATK + DEF)/700 + Changes in stats based on effects = Level (Rounding Up)
This formula tended to work when I made it up, now it doesn' seem to work as much, but I like to retain when an ATK of 1600 and a DEF of 1200 was considered a strong Lv.4 Monster.