Aftermath Analyst is a half-step behind the truly best-in-class ETB creatures in terms of cards milled, but its still cheap to cast and has the many advantages of creature cards: attacking, blocking, ease of recursion, and so on
It wouldnt matter, since multiple decayed triggers wouldnt change the way the mechanic plays out
Slivers excel at flooding the board with creatures
I have the pleasure of interacting with nearly every product we create, so I am "uniquely positioned to write an article that goes into detail on all of the Core Set 2021 products" according to the mean product architect who didn't want to write this article himself
Finally I can announce that I am a Disney Lorcana artist
You can also get it on protection like Restoration Magic, and on removal like Noxious Gearhulk or reanimator creatures like Metamorphosis Fanatic