>>3122871Judging from the filenames, you probably got those pics off Messenger, right? And who knows who sent them to you, but there are many sites such as Facebook where pictures go trough horrible jpg compression when they're uploaded there.
Try to post high quality images, preferably from the artist's official pages where the pics are at their best quality. Asian artists usually post their art on Pixiv, Twitter, blogs, and even Tumblr and (rarely) deviantART. Use SauceNAO to reverse-search a picture first and then Google Images if SauceNAO didn't help.
Only if the original source is gone, your next best option is to save the art from a site such as danbooru or Zerochan. For example, I saved this pic from danbooru because the original from Pixiv was deleted.
If everything else fails, you can then post the best quality version you can find on other sites.
I hope you find really cool art and discover new artists this way.