7SPOT Rally Mew Event

"So rare that it is still said to be a mirage by many experts. Only a few people have seen it worldwide."

7SPOT is a Wi-Fi service that is hosted throughout multiple Seven & i Group stores all over Japan (e.g., 7-Eleven). 
Aside from it’s internet allowance, 7SPOT sporadically gives consumers special gifts. 
As of July 11, 2017, players can use the Nintendo Zone app to receive serial codes to obtain the Pokémon Mew for use inside Pokémon Sun and Moon games.

Midday on July 10, 2017, Wonder Card ID: 238 -２０ＴＨ☆ Mew was uploaded to the Wonder Card servers in preparation for the 7SPOT event.
Naturally, this WC was added to our Event Gallery as soon as it was available.
This led to the first report from one of our users that this event contained an invalid OT.

Before the official release of WCID 0238, it was revealed that after trading this ２０ＴＨ☆ Mew, the Original Trainer (OT) would change
from “２０ＴＨ☆” to the version name and save language of the 7th generation game in which the Mew was received. 
Check out the visual below in the spoiler, for examples of this occurrence.

This type of “censorship” in where a Pokémon’s OT and/or nickname can be legally changed (upon transfer or trade) and has been around for quite some time.
Typically, it affects OT and nicknames that contain profanity and/or character-symbol discrepancies.  It is also worth noting that there were previous Event-Pokémon
that had invalid OTs as well. One of our Event Contributors, Kirzi, has posted about this in the past and has provided a list of those events.

Shortly after the event started, which was at 7am (Japan Standard Time), theSLAYER found proof that, in fact, players were receiving the invalid 238 - ２０ＴＨ☆ Mew
and it wasn’t until nine hours after the event started that the Wonder Card ID was changed in the server from 238 - ２０ＴＨ☆ Mew to 238 -２０ＴＨ Mew.

Closely following the situation, theSLAYER found proof that the fixed Wonder Card had been successfully redeemed by multiple players shortly after its release.
(And thanks to our dedicated Contributors as well for uploading their Wonder Card files!)
However, approximately 30 minutes after the fixed Wonder Card had replaced the Invalid one, another WCID appeared on the servers, WCID 247 - ２０ＴＨ Mew!

There is much speculation around this third Wonder Card and why it appeared on the servers after the fixed 238 was re-uploaded and then distributed again. 

Images: 7SPOT, theSLAYER
Sources: 7SPOT, theSLAYER, Kirzi

Related:
ongoing discussion