pokemon card toxicroak ex It's Poison Time: Plus Friends Psychic Rarity Toxicroak EX [1st Edition] #36

Between this and the fact that blacks best mana ramp spells only tend to thrive in specific niches of the Commander format, such as cEDH, mono and two color black decks, combo decks, and/or builds with reliable access to Urborg, Tomb of Yawgmoth, theres really no way to rank these cards

The activated ability does tons of work since you want to play these effects in a go-wide deck

Note: Many of the cards discussed below could fit into multiple categories (Vorinclex, Voice of Hunger acts as a Stax Piece against enemy lands, but also provides Fast Mana), so I'll arrange them via their most common application

While so fun, Nettling Imp is a little too cute for this deck