Mirkwood Elk is just beat out by better elves that regrow creatures from the yard, Radagast would really rather play with Tawnos and Mirkwood Trapper just doesnt do enough to justify the deck space
Not only can you play a cost 6 (or less) Song for free when you play him, but he also counts as a 6 cost character for playing other Song cards too, thanks to his Singer 6 keyword
A legendary vampire general who doesnt even need to leave the command zone to strike fear into your opponents
Tocasias Welcome White has slowly been accumulating card draw options over the past few years, and at the time of publication, I think white can draw a reasonable amount of cards especially if it can chain the right engines together (looking at you, Skullclamp)
That means it won't mutate, it won't be able to do anything but have an enters-the-battlefield effect or maybe make use of counters
Twilight Sparkle is thematic for a "group hug" deck, which means that you're going to give your opponents a lot of opportunities to draw cards and yourself a lot of opportunities to get Treasure