@01189998819991197253 doing a tiny bit of research, it seems that they’re mostly known for EDC-style pens. The fountain pen isn’t even on their site.
For $20 I would probably stick with a better-known FP brand. What specific requirements do you have?
@Rhaxapopouetl ah— fude nibs are a bit tricky in Europe, not many places carry them. Etsy might be an option, they recently started charging VAT for Europeans, so you shouldn’t have any import issues. Some stores to look at are esybuy, ChinesePen, and PenBBSOfficialStore.
@Rhaxapopouetl also, Wing Sung 698 takes #5 nibs, so you can move your fude from your Hongdian to that pen and it should work fine.
@Rhaxapopouetl Wing Sung 601 I believe has a fude nib option and very large ink capacity. PenBBS has a calligraphy No. 25 nib which is a small fude, and would fit their piston fillers (I use the 456 and 495). I believe Sailor Fude de Mannen can be eyedroppered for more ink capacity.
@JakeSparkleChicken some of the Manyo and Yurameku inks are prone to change colors with oxidation. This is a known thing and at least partially intended, though I can’t speak to the specific change you’re talking about. But I wouldn’t assume anything’s wrong with the ink in terms of its being safe for use in a pen.
@01189998819991197253 In this price range I'd suggest looking at Pilot Lightive or Platinum Plaisir.