In contrast, Faces of the Past is an MTG card that can go in any blue-aligned typal deck
Even better, Tortoise discounts the cost of filter lands like Twilight Mire and Sungrass Prairie, allowing you to actually net mana from those lands
On the flipside, if your key engine costs a ton of mana, like Kozilek, the Great Distortion, a big beefy ramp card like Thran Dynamo will get Kozilek out much earlier than a Mind Stone
If it gets out, the advantage it will offer you is off the charts
It's a nice way to drop a big flier on the second or third turn
Four of these in a deck offer a ton of utility in Standard play, but it's perhaps a bit of a "blink, and it's gone" card in Commander unless you have a way to bring it back from the graveyard to your hand