Besides its obvious implications in Mardu EDH decks already built around attack triggers, in formats like Standard you can benefit from multiples of these
The creator keeps the capital as profit, not inventory
When paired with ways to abuse this effect, such as Creeping Chill and Narcomoeba, it is quite easy to gain a huge edge without spending much mana at all
6 Liliana, Dreadhorde General Queen Of The Undead 6 Mana Cost in Black Planeswalker Another Planeswalker, and another reprint, Liliana embodies the personality of black mana cards in one package
Theres no real way to get these boxes on the cheap
8 Add: Dragonspeaker Shaman Cut: Harbinger Of The Hunt Easily one of the best cards to run in a Dragon deck and a surprising omission from the base deck, Dragonspeaker Shaman does just one thing but does it exceptionally well