Probably, the reason for the ban was the Nazi symbols featured in both videos.
On November 10, 2017, from the next update of the Federal List of Extremist Materials, we learned that clips banned on September 7, 2017 by the Kurgan City Court were included under numbers 4289 and 4290. The first one is "The Great Rap Battle - Putin vs. Hitler" (video starting with "Ladies and gentlemen, welcome to the non-f*cking rap battle...", ending with "...choose one of the alternate endings, epic the rap battle continues)". The second one in the court decision is called "In the style of the group Krovostok - Ziga (RAP)" , zig hael, oh *la, sorry)"), but this refers to the video for the song "Su zhitul" by the group "Vietnam Recitatiff".
From our point of view, these clips are illegally banned. They contain Nazi symbols, obscene vocabulary and pejorative ethnonyms, but both of them are not aimed at propaganda of Nazism and do not contain any aggressive appeals. One of them parodies neo-Nazis, the other is also satirical: it criticizes Putin's policies and ridicules the mutual accusations of Russia and Ukraine of fascism. It seems to us unjustified the ban on any display of Nazi symbols, prescribed in Russian legislation, regardless of whether it is related to Nazi propaganda. In particular, significant doubts about the adequacy of a total ban arise when it comes to art.