During the Main Phase, if your opponent Normal or Special Summoned 5 or more monsters this turn (Quick Effect): You can Tribute as many face-up monsters on the field as possible, and if you do, Special Summon this card from your hand, then Special Summon 1 "Primal Being Token" (Rock/LIGHT/Level 11/ATK ?/DEF ?) to your opponent's field
Then when it dies, flip to the land and then you can flip back for three or just tap for mana if needed
Players also have a 0.05% chance of finding a God Pack, which contains all cards with a gold star rarity or higher
You have to pay a truck load of mana (7, 10, 13, 16, etc.) to have this even do anything, and the effect itself is of course completely unreliable
The Legend Rule as a Balancing Mechanic Whilst it may not have started with it in mind, in more modern design I'd argue that the legend rule is far more important as a balancing mechanic