D.Y1: tenretni olleh

This YouTube channel, whose name is "hello internet" backwards, was hidden in the tags of the trailhead video (D.Y0).

The channel has an icon consisting of an upside-down silhouette of the Game Theory logo and the text "pow zNb Xdd MnH" and a channel banner with the text "patience is the key" repeated 32 times in four segments of eight, with a slight gap at repetition twelve and 24. By taking the gaps, the text is grouped into groups of eight, four, one, three, four, four, four, and four, respectively.

The text in the logo was interpreted as "HuW ppX qNz mod" and used to unlock D.E1.

"Patience is the key" may refer to the waiting game set out in D.E0, but may also be the literal key to a future cipher.

As of 09/29, the banner has been edited to be black with green text “hello theorists, have you come to play?” Analysis of the image reveals the word patience hidden in the bottom-left corner.