The downside is you need to be able to recur the lands you sacrifice for the ability
Crux of Fate as an ultimate is cool and all, but Crux isnt out there auto-winning games or anything
The Crafter of Plagues is a 3/2 that forces everyone, yourself as well, to sacrifice a dork or planeswalker on arrival to the battlefield, and you can sacrifice him to himself to trigger Bane with a two-toughness death
I love that I can buy a nonfoil that is a bit special, because tournament players dont like having just a few foils (pretty easy to pick out warped foils in a deck) and I especially love that this always gets played as the full playset
Lotus Vale / Mox Diamond / Phyrexian Dreadnought More cards that had their functionality disrupted by a rules change
The tweak here, and I find it quite compelling, is that you can use any creature as a resource for this shrinking