Around September 9th 2020, a program was leaked, and said program allows the creation of 2 games: Slot-2 Distribution and Wireless Distribution. The program comes with a few templates, and it replaces part of the template with a selected script, in order to distribute the event.
From within either template (Slot-2 Distribution and Wireless Distribution), a Pikachu test event was extracted via hex editing.
If this template was used as the final slot-2 distribution game to distribute to Gen 4 games, the Gen 4 game will freeze.
Due to natures of the Slot-2 distribution game, only Japanese games can detect it thus far.
If distributed wirelessly, it appears that the card will be the exact same, except that a date is written by the receiving device.
[We will not distribute the Debug ROMs or the template ROMs used, and it is against our rules to ask for it]