I personally don't agree with the idea of using a deck someone else made. There's no context for where the cards are coming from, they're harder to remember, and really only good for short term sprints. It's why most people fail at learning Japanese quickly. They think it's faster because the deck was already made for them. That somehow quantity of study resources = faster learning. The journey of making your own deck is what will push your Japanese to its best in the shortest amount of time. You'll get the context from where you initially find the sentences. You'll get bonus words from looking up the definitions. Eventually you will even move into Japanese-Japanese flashcards personalized to you. Personalization is the highest form of context. The better the context, the better you remember, the easier it is to learn and use Japanese in real life.