P.S.A for deck building!!!
DD2 has a crafting system and if you want specific cards, it's better to craft them than to roll.
1️⃣) There's videos that go into better detail, but from what I remember when you first craft a card you don't have, it'll cost a lot, but then it'll cost half as much afterwards. HOWEVER, if you decide to craft say multiple Rezaels at once, idk if the game charges you for the first price, or discounts the following ones.
2️⃣) When you get more than 4 copies of a card, the game will automatically dismantle it into CP for you, which is what you use to craft cards. The higher the rarity and print, the more CP you'll get, and since you can only ever have 1 Over trigger, and 1 regalis piece in the deck, you only need to pull 1 of each to dismantle the rest into 2000 CP.
3️⃣) So, the best way to get a lot of duplicates of a card is to roll for a cheap set with a small card pool, and I recommend the most, Festival Set 2024, I believe it's in the shop under DZ-SS. It only has a 68 card pool, 2 OTs, 2 Regalis pieces, and a few generic good cards for all nations, so it's a wonderful starter set.
From there, it's just a grinding process for VP playing through the story mode. OH! There is one more important thing, I believe as you progress through the story mode of DD, you'll unlock a D-skill that increases your earned VP. Blitz through the story mode with a decent deck to aquire this skill and then grind like heck for VP to eventually craft all the cards you want