Kicking off the multicolor cards, Astor, Bearer of Blades, gives us a solid role player in decks using vehicles or equipment
Warp, foretell, cascade, and Adventures all cast from exile, and with three colours Ghost-Spider has more than enough cards available to it to get nice and big before it attacks
For example, if you have a card with improvise that costs and you tap two artifacts, you only have to pay to finish casting that spell
It works best in flicker shells that use it as a card draw engine in addition to interaction
You need answers for all types of permanents and have only so much room for removal, so flexible removal that can deal with multiple types of threats is crucial