I can't convert those subtitles from .sub to .srt format. Can you upload as .srt format too? Best regards.

Akuma_Blade just drop the subs in the anime folder and you're good to go.

Akuma_Blade from sub to srt there's a software called subtitleedit you can use it to convert the subs

The conversion is not simple, since the format is picture format so the converter needs to make OCR. I had done it many years ago and I remember the issues (not only problems with detecting "I" (uppercase i) and "l" (lowercase L)). There are many converters online now, try to search: "convert idx to srt"

Discotek subs are not the worst to OCR but they will still require some QC work

Well if someone goes to the trouble to OCR this I hope they share it.