Man, if the manga follows the LN(or is it WN), then I might have to stop reading, a.k.a stock up chapters til at a point where there won't be a heartbreaking cliff for me to read.
@Sonic the latest chapter over on Seiga is chapter 18. How did you get this chapter? Nevertheless, you might need to be aware of Rule 2.6: Uploading a scanlated chapter before the official raw chapter is released in the original country is prohibited, unless an appropriate delay is used.
@Maiorem seiga isnt always the best source of raws and is often late in releases for a lot of manga. If you look hard enough you might find the raws updated earlier on a different site.