I'll always make time to attend a Watain show whenever they're near my neck of the woods. Being covered in blood afterwards is a nice extra.
As to an official Oldhammer band, perhaps 'Castle Rat' could fit the bill? Nice retro vibe, solid Fantasy setting, kinda like an oldhammery metal version of 'Hellas' which are great fun too.
It must be years and years ago that somebody on this very forum mentioned the "Dark Brittanica" sampler as an ideal painting soundtrack. All four volumes are still being used for this purpose today.
I've found that most of black metal makes a poor painting soundtrack for me, so I've branched out into a variant of it kids today call 'Dungeon Synth'. Turns out, a lot of recluses everywhere like early Mortiis or Varg's jailhouse synth albums even more than I do, have picked up those torches and run with them.
Solid choice! That's what i'm talking about. Silenius's side gig 'Mirkwood' is great too. Other favorite painting bands include 'Elffor', 'Thangorodrim' and of course 'Emyn Muil'.
These days, I like to browse around the dungeon synth archive channel and give some of the very recent uploads a try.
https://www.youtube.com/@TheDungeonSynthArchives