mtg arabian nights card back Sold at Auction: 1993 Shahrazad CGC 6.5 destroy all creatures blocking or blocked by it Magic the Gathering Arabian Nights

Thats about as smooth a ramp as you can get, but you can also add three counters, then double a creatures power and toughness and give it trample until end of turn

Urza's Command can drop the power of other player's dorks out of nowhere, make a Powerstone, make a tapped Construct token to win the game, and then scry and draw, so I think that the Construct and scry and card draw are the default here, and that's pretty good for four mana instant speed

I wouldnt use them as more than 50% of the ramp in your deck

Cloud, Midgar Mercenary Cloud is cheap, powerful, and presents a unique card that should be viable in a number of formats