Thinking on this topic again because an associated topic was brought up on MaRo's Tumblr.
The way the Phyrexian Invasion of the Multiverse in March of the Machine was handled was very badly done on two fronts.
The big one was putting basically the entire war into one set (and change). The start of the war itself was at the very end of the story of Phyrexia: All Will Be One, with the opening of Realmbreaker's Omenpaths.
But the war itself was basically over as soon as it began because of a single decision in-universe that wasn't revealed until after things ended, and even then it was only speculated by the characters. Namely, that Elesh Norn had decided to anchor all of New Phyrexia's Glistening Oil to herself.
Now, I'm not one of the people who wanted New Phyrexia to win and the next storyline to be the multiverse slowly fighting back. But I think it should have been harder than "Wrenn sacrifices herself to save/stop Realmbreaker" coupled with "Elspeth chops off Norn's head."
In my opinion, the story should have had the heroes fighting as hard as they are able, losing some places and winning in others, all the while hunting for a way to win outright. Show the big names fighting for their homes or trying to find a new Legacy Weapon, what with Karn captured and dismembered and the Weatherlight compleated.
And then, while being compleated, someone figures out what Norn did and tells the people around them. The one coming to mind being Grist, who is a hivemind. They'd recognize that Norn has basically done to New Phyrexia what they do to insects.
And then you get an attack on Norn and, while there, Wrenn suddenly realizing that Realmbreaker needs her help.
Have all that over the course of two full sets.
And then, the second thing, don't do the Aftermath thing. Instead, have the players discover the effects of The Rending with the characters. Each new deSparked Planeswalker coming to terms with it better and better as time moves past.
Some unbelieving that their Spark is gone, some deciding that they're okay with staying wherever they landed for good, others mapping out the new, chaotic Omenpaths so they can keep wandering the Planes, even without the ability to control their destination.
And someone trying to pull a Bolas combined with a Yawgmoth to try and gain their powers back, even if they have to steal it from someone else.
Ending the main event the same set it started left things feeling unresolved. Shoving the results at us without fanfare afterwards made it worse.
They said "look at Sarkhan, looking happier than ever" about his deSparked card's art. But why should he be? They never gave us his thoughts on it, just told us it must be a good thing.