I’ve been collecting Pikachu in all languages for the first 25 years of the Pokémon (up to Feb. 27th, 2021) and have been collecting Pikachu for roughly 9 years now, and Seviper in all languages as well for about 6.5 years.
Since I started collecting Seviper a few years after I was already collecting Pikachu, it wasn’t too hard in general. I knew where to find most English, German, French, Italian, and Spanish cards (so to CardMarket I went), and although some took some time to emerge on CardMarket, in about a year I had all of those. Japanese wasn’t too hard either, except for two unlimited edition WCP cards - which took me ~3.5 year to find and were the last two cards I needed at the time to 100% complete my Seviper TCG collection.
For (Brazilian) Portuguese I had quite some issues the first ~4 years of collecting. It wasn’t until I found an amazing Brazilian middleman (iirc he actually contacted me after he saw my Pikachu collection video on YT. ), who helped me get from ~25% of Portuguese cards for both collections, to 100% for Seviper and 99% for Pikachu, which he all found locally within two weeks. Only the 1st edition Jungle Pikachu he wasn’t able to find, which I later pulled from three booster packs I bought myself. And he had been helping me with new releases since.
For Seviper, these days it’s mostly the non-Japanese Asian languages (Korean, T. Chinese, Thai, Indonesian, S. Chinesse) which give some trouble. Luckily, I still have an active Indonesian middleman, as well as a friend from Singapore and a Chinese guy currently living in the US, who help me with the Korean, T. Chinese, and S. Chinese cards. Only the Thai cards are a bit more troubling lately, but luckily they do end up as singles on eBay or OjamaCard eventually with time, in my experience. So my Seviper collection is re-completed again. There are still two SwSh and SV era artworks that might release in Simplified Chinese perhaps, but apart from that it’s waiting for a new artwork to release, and I’m therefore mostly focusing on the non-TCG Seviper portion.
Pikachu on the other hand is a much different story. Especially since it not only has cards in all 15 available TCG languages, but there are just so, so many and it’s very hard to keep up with new releases, both in terms of time-consumption and financially (e.g. in 2019 a total of 233 Pikachu TCG cards were released). Which is also why I limited myself to the first 25 years, and stopped collecting all languages for cards released after February 27th, 2021 (with some exceptions), since it just wasn’t fun anymore.
But Pikachu also has not just language-exclusive artworks and cards, but even a lot of country-exclusive releases. There are English Pikachu cards exclusively released in these respective countries: Sweden; The Netherlands; Canada; the UK; the US; Singapore/Malaysia/Philippines/HK; there are French Pikachu cards exclusive released in Canada and/or Belgium; Spanish cards exclusive to Argentina, Peru, Mexico, and/or Chile; there is an error release where the English and German releases were correctly released in their respective countries, but the French and Italian releases had one of the four languages at random in the product (I’ve ended up buying my French copy from an Italian seller and vice-versa More than a year after they were released…).
Still, the journey and collecting itself is a lot of fun, as well as the friends and fellow collectors you meet along the way. And when you do eventually find those hard to find cards, it is an amazing feeling, and also fun to look back on years later. To give some examples by quoting myself from my collection thread, of cards I was able to add to my collection years after searching for them:
Apr. 2017: Japanese 102/DP-P Pikachu (rare Japanese Pikachu card at the time)
Oct. 2020: Japanese unlimited WCP Seviper and Japanese unlimited edition Web Booster pack containing Moltres (final Seviper TCG card across all languages, and a rare sealed Moltres variant)
Jul. 2021: Japanese unlimited edition E1 Pikachu (very rare Japanese Pikachu)
Nov. 2022: Swedish sealed Moltres promo (final sealed Moltres variant)
Sep. 2024: English Ashley Art Academy Pikachu (final English Pikachu card)
Right now, my Seviper TCG; Moltres; FA Supporter; Ancient Mew PSA-10; Swablu; and first card per language collections are all complete, and I’m primarily just keeping up with new releases. For Pikachu I’m missing just 9 cards, and I’m almost at 2k Pikachu cards in total (1867 with 5 incoming to at time of writing, to be exact). And my main focus rn is Seviper non-TCG stuff (for which French items are indeed more expensive as well ).