Download a YT video as an MP4
Clip and cut out the part of the video you want to use for the gif, then download that
Select Video to Gif with that clip, then add subtitles at the timepoints in the clip and download that (or save the link in the address bar to the finished clip
Take that downloaded clip with subtitles (or the link) and post it on Imgur, either as the file or as a Vid to Gif