EDIT: I just walked away from my laptop and had some time to think I feel this is more of a want in the matchup (just like Lands) than a need but I dont feel its incredible
Legion Warboss Legion Warboss uses its mentor ability to swing in with a 2/2 goblin each turn, assuming you can protect your Warboss in combat
Unlike the previous set, this grabs your deck so you built around it
"The calendar goes further and talks about the Elder Land Wurms being those of the Elders that were stripped of their wings during the ancient war." So that is where the Elder Dragon War, the origin of the Elder Land Wurms, and presumably the idea that the five Elders are the ancestors of all dragons in the Multiverse, come from
And after that, there will be no creases or cracks on them
The original Archenemy and its sequel are great, and the latter is especially flavorful, but theres really no substitute for Commander