So a quick google translate Japanese to German later (because I'm too lazy to change it back)
And 墓守の一族 イシズ..... is Ishizu. So Either it's saying Ishizu's Brother, or Ishizu is getting an event and not a new character.
i was searching that words and one possible translation is "Ishizu: Clan of the gravekeepers" so maybe the next event are going to be about the history of the ishtar family...
It really doesn't. Why would an Ishizu event unlock regular Marik? They'd probably do a Marik event for that, or tie it in to a Battle City re-run or something. >.> It's obviously a "Super Ishizu" event, and thinking otherwise is dumb.