PuPu UFO and Zell Dincht give you extra land drops, and Zell's drawback (bouncing a land back to hand) may actually be a plus with Sabotender, giving you more ping fuel
Omega, Heartless Evolution Looking for a hulking finisher that also locks down the board
Donating one of these to a creature-heavy deck can be crippling
The ability might not be as broadly applied as Grumgully, the Generous, but Metallic Mimic is a cheap colorless card that can apply to many more decks
Shadow's effect isn't once per turn , so you want to only cast spells when you have an artifact to tap for them, so no opponent can interact with it and it'll always resolve
I'll admit I was initially a little worried about Tarkir: Dragonstorm , especially when Final Fantasy card previews started to pop up first, despite Tarkir being next to release