Curse of Dragon only requires one Tribute summon to get it to the field so if you need a strong monster out as quickly as possible, this can help at least and as mentioned earlier, Dragons have a lot of support to make them even stronger so Curse of Dragon is a strong Dragon monster you can send out and power up quicker than some other more powerful beatsticks
Emergent Ultimatum is still on the stack while you cast the cards you found, so those spells could target it
Every single decision up to this point in the game suddenly becomes pointless
Luckily, these decks have a new engine that facilitates their plays, as the Primite engine is useful for this purpose, and Primite Dragon Ether Beryl is a reliable normal summon
While the choice of color roughly equates to the Pokemons exclusivity (Where Pokemon available in both games feature a split background), this isnt always the case
I am accustomed to card games where the same card, even with different art, has the same behaviour but here it seems that you can have variations on a theme