Go to your local manga store, they have a bunch of stuff, mb its in there

How about supporting the series by buying official merch or buying physical copies, but still read unofficial online releases? Don't make it hard on yourself. Artists take value on their art being appreciated.

Do you mean from an EU company or just generally available in the EU?

In case of the latter: I'd recommend Kobo. I use that for most of my digital manga reading. Berserk is on it too (am in EU as well, not sure if same country. That might impact it). Kobo ebooks are also really easy to remove the DRM from.

Why is it being legal so important to you?

If you are fine with Google stuff: https://play.google.com/store/books/details?id=ewQtDwAAQBAJ

Otherwise, try eBay if you can't find a bookstore near you.

Or try finding one in a nearby country that ships internationally.