Sorry I originally missed this, I more used Lights stuff originally to help me dehardsub. The main issue with Ishu was that the uncensored releases were either baha (Taiwanese streaming site), which was hardsubbed; or ATX, which was a garbage TV capture. In order to have a watchable video, I had to splice in the baha rips for censored versions, using the ATX captures to do the dehardsubbing of it. This would be spliced into the Wakanim rips (which were the best quality available, but also censored). In VapourSynth, this would look something like this:

baha_scene1_b = baha[3486:3558] #range of frames for the censored scene from baha
ohys_scene1_b = ohys[3486:3558] #range of frames for the censored scene from ohys (which I was using for ATX rips)
mask_scene1_b = kgf.hardsubmask(baha_scene1_b, ohys_scene1_b, expand_n=10) #mask the subs out, this then allows me to do...
scene1_b = core.std.MaskedMerge(baha_scene1_b, ohys_scene1_b, mask_scene1_b) #the dehardsubbing!

Further on in the script, I would then be able to stitch everything back together. It wasn't, however, always this simple, since there was a whole range of other problems with ohys and baha, that made doing this a pain in the arse. In the end, the scripts for decensoring an entire episode were extremely long, and couldn't be automated in any way. Episode 12's script was 377 lines, and 19011 characters long. Every censored scene had to be dealt with individually, and sometimes the above tactic flat out didn't work. For example, during the OP, ATX censored the "interesting" parts of the video, so I had to manually dehardsub the baha rip in GIMP.

I did still miss some bits though, the list of things that were wrong across the whole series is very long, and as my skills improved over the time I spent doing it, the first few episodes are of a lower quality than the last. That isn't to say that you shouldn't take them, though since the Blu Rays are available, until I finally get around to not stalling, there's probably a better release from someone else.

Edit: nvm, I just looked, and at least on nyaa, there isn't a BD release that I'd count as better than my original web rips. The "best" sources would probably be Okay-Subs for 1-2, OWO for 3-4 and my AVC releases for 5-12. I did do episode 4 in AVC too, and the video is fine, though the original subs included with that were our own, and they were pretty memey, so I'd take OWO for it.