Keywords and mechanics dont get as many support cards as creature types do (if they get any at all), but they can be surprisingly powerful, and they take your deck in interesting directions
What it costs: Competitive Pioneer decks typically run $150 to $400
You may cast the top card of your library if it's an instant or sorcery card
While its ability to replace self is a definite bonus, having the repeatability of Penance or Hidden Retreat just stood out as a better option
It still sees a good amount of play in Pioneer, although this is usually in Greasefang, Okiba Boss decks
Putrefy & Mortify If Bonecrusher Giant shines by being a Jack-of-all-Trades, Putrefy and Mortify are what you expect from specialists: Get the exact job done, done well, and with no drawbacks no cute 3/3 elephants to worry about here