I think the goal of adding black was giving players access to a plethora of sacrifice effects to make use of the recurring nature of other phoenixes
I looked for expressions with General in them
This card confused a lot of players
(2022-04-29) You choose the creature as the spell resolves
While running a deck with just permanents that cost two or less mana in Standard mostly limits Lurrus of the Dream Den to very aggressive shells, playing Lurrus, of the Dream-Den as your companion becomes much easier in older formats, which place a higher value on efficiency
While playing Sylvan Library in a multicolor deck might sound strange because it only grows green creatures, if you look at a Gruul Aggro decklist, you'll see that outside of Bonecrusher Giant (which we can consider a removal spell), the list is almost exclusively green