one piece op 5 booster box you can get previously released cards with [PBR One Piece OP 05 Awakening

You can obtain the Dialga ex (3-Stars rarity) card by opening Space-Time Smackdown: Dialga from Space-Time Smackdown set

Supreme King Dragon Dark Rebellion X DARK Rank 4 [ DragonXyzEffect ] ATK 2500 DEF 2000 2 Level 4 DARK Pendulum Monsters Once per turn, before damage calculation, if this card battles an opponent's monster: You can detach 1 material from this card

If everything costs six mana, you're going to be way behind on playing creatures, and if everything costs two mana, you're going to get outclassed in the late game

Borderless come in regular booster packs, EA only come in Collector Boosters

That can be accomplished with +1/+1 counters, -1/-1 counters, anthem effects or even auras or temporary pump spells