[2021] New Yordle Champion Shown on "Rise of the Sentinel" End Screen

Here's a screencap: https://puu.sh/HUlsY/02ac9b5c0e.png

Here's the video link: https://www.youtube.com/watch?v=RAw5aTmf9Og

Some people think its Xayah or Poppy, too, I can see the resemblance but I am pretty confident this is the new "gloomy yordle shadow mage" that was delayed (she was supposed to release before Akshan).

When do you guys think she will come out? I almost think there might be a part 3 to this ruination event with Akshan, her, and more ruined skins (hopefully the leaked Ahri).