One idea could be a rengoku fanfic where he trains a new group of young slayers. It could focus on his unique teaching methods and how he instills his values in them.
Tanjiro would be a great character to pair with rengoku. Their different personalities could create an interesting interaction. Tanjiro's kind - hearted nature and rengoku's fiery determination could lead to some great storylines.
One of the main themes is adventure. Since rengoku is often involved in battles and dangerous situations, the fanfics may take the reader along on these adventures. They might face demons together and their relationship develops through these shared experiences. Also, loyalty is a big theme. Rengoku is a very loyal character, and this loyalty extends to his relationship with the reader in the fanfics.
There were a few software programs that could be used to make gifs. Among them, Waifu2x, Dain/Cain/Rife, Squirrel-Rife were some of the software that was mentioned. These applications all used deep learning algorithms to generate high-quality in-between frames, making gif animations smoother. In addition, Veed also provided an online GIF frame rate translator that could help users change the frame rate of GIFs. These software had their own characteristics and usages, and users could choose the appropriate software to fill in the gif frame according to their needs.
Celebrating the Year was a very popular TV series. In it, Fan Xian and the Second Prince were described as walking emojis. Their expressions and actions brought a lot of fun to the audience. Fan Xian's childhood expression package included the cute way he ate and the perfunctory expression. The Second Prince, on the other hand, had become a meme in the hearts of the audience with his happy and humorous image. The emoji packs of the good guys and bad guys of Qing Yuannian were very popular.