Neurok Transmuter seems like a fairly standard idea for cards-that-play-around-with-artifacts that one would expect in the Mirrodin setting. He can turn creatures into artifact creatures, or artifact creatures into nonartifact creatures... that's bound to have some strategic applications here and there. The thing is, that second ability is pretty unique. How often do you see a card that can remove a type from a permanent? Now, again, he can only target creatures - you can't remove the artifact type from your Sky Diamond or whatever - so you'll always be left with a nonartifact creature.
Or will you?
There are a number of artifacts that can temporarily turn into artifact creatures, making themselves valid targets for the Transmuter, but these effects generally end at the end of the turn, the same time the Transmuter's effect stops. There is one weird and classic exception, however:
The humble, pioneering Jade Statue can be turned into a creature only until end of combat, after which it reverts back to being a plain ol' artifact for your postcombat main phase. See where I'm going with this? During the combat phase, you can animate Jade Statue, then target it with Neurok Transmuter, turning it into a blue creature. Then, after combat ends, it stops being a creature... but wait, it also stopped being an artifact! So what is it? For the rest of the turn, you are the proud owner of a (blue) permanent that has no types. It's not an artifact, it's not a creature, it's... just there. Amusingly, being typeless makes it surprisingly resilient to removal - basically nothing short of Vindicate or Apocalypse can take out a typeless permanent.
Since we've already noted the abusiveness March of the Machines allows for twice in recent memory, I might as well point it out here as well: this headache-inducing enchantment likewise pairs with the Neurok Transmuter to produce typeless permanents. In order for March of the Machines to turn something into a creature, it must be an artifact in the first place. So if it turns an artifact into a creature, then the Transmuter makes it no longer an artifact for the turn, then the March will no longer make it a creature. You see? Typeless permanents on demand! Throw in Moonlace and they can be colorless as well as typeless. What you can actually do with these no-type wonders is up to you to figure out.
