The Powers of the Mind Very Rare sheet contained two copies of each of the 48 Very Rare cards & one copy of each of the 4 Entity cards. This sheet was likely cut and directly distributed into booster packs, meaning that 1 out of every 25 packs contains an Entity, and 11 out of every 25 boxes will contain 2 Entities (44%).
Note that the depicted Print Sheets are just example layouts. I don't know what the actual card layout of these sheets were. In fact, the actual layout was likely more randomized to make it easier to pack boosters.