Ulamog, the Ceaseless Hunger 7 New Ulamog is a fair bit better than the old in these kinds of application
Your engine piece will eat a disenchant
We also haven't heard anything from Huey Jensen - who was involved in extending Standard rotation - in ages
(Megamorph, the alternate-reality version, was not as much a hit.) I really like how manifest shows that you can take a core good design idea and extrapolate it to make something related, but different, that's equally fun
As for uncommon payoffs, the deck has some nice legendary creatures like Uncommon payoffs like these are a real draw for an archetype like this since you'll have cornered the market on them
Alliances was a pretty revolutionary set, and Thawing Glaciers was an important part of that revolution