If a creature with undying stops being a creature (for example, an artifact creature with undying becomes a noncreature artifact due to Neurok Transmuter 's second ability), undying will still trigger
To the best of my memory, here's the original design (with updated templating): Killing Machine 5 CARDNAME enters the battlefield tapped
Flickering this gets deadly faster than you would think, and it also server to pick off their creatures at the same time to help keep yourself alive to do it
Over time, it became clear that factors such as security, insurance, and ongoing costs play an increasingly important role
That said, I love to showcase it with lists like this, and I hope you enjoyed reading it as much as I enjoyed writing it