Some slots in the set booster can be any rarity
Do not hesitate, you always use your Leader ability to take one Don on 3 or 4
For most decks, Thran Dynamo is just as good as Gilded Lotus but in others, you need colored mana to keep going off with your combo with Engine which necessitates this
It's most often played in decks that are casting a ton of spells so you can always cast it by exiling six cards from your graveyard, or ones that are reanimating it directly from the graveyard
In the Darkness Bind Them churns out three 3/3 Wraith creatures and has the Ring tempt you, and with the final chapter temporarily steals the best creature from each opponent so that you can attack with them
as well as non-combat reuse of comes-into-play creatures (Jilt your own Flametongue Kavu, perhaps?) Barrin's Spite was a rare in this block and served generally the same purpose as Jilt, except that Jilt was an instant, and Jilt allowed you to unsummon your own creature if need be