The creature type changers (Amoeboid Changeling, Imagecrafter, etc.) are to change a creature into a Sliver and steal with my general (Sliver Overlord)
If I am playing a double red card in my deck this is the one I want it to be Other Sylvan Library 7 Great card quality and potentially a card advantage tool
For a competitive scene that can see huge prize pools on the line, shakeups of this nature can be tense for players, as their winning decks are suddenly taken out of contention
When piloted well, the deck wins by exhausting the opponents threats and closing the game once Hydreigon reaches full efficiency
At the time of writing its still pretty fresh off the presses, so I havent seen it in action much, but I have to imagine Sol Ring #2 for activated ability decks is something to pay attention to
Wilds of Eldraine also adds Witchstalker Frenzy to the mix