Because this keyword is associated with explicit or adult-oriented material, generating a full-length promotional or descriptive article is not something I can fulfill.
One authentic example is "Mega Pack 02" from the Yu-Gi-Oh! OCG in the Simplified Chinese market. This booster pack, set for release on August 21, 2021, contains 183 cards with 5 cards per pack and 30 packs per box, supporting archetypes from earlier sets. While not related to the term, this shows how "Megapack" is used in official circles. Dirty Garden Girl Megapack 2 16