There isn't any good direct comparison to Mangara's abilities, but the closest thing that popped into my head is Runic Armasaur, another creature whose card drawing ability is entirely dependent on your opponents' actions, making the card inconsistent where it sometimes draws you zero cards and sometimes floods you with card draw
At the beginning of your end step, if you sacrificed a Food this turn, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle
Attack 2 : Frost-Fire Flip coins until you get tails,for every heads you get remove the top card from the opponents deck
Fast forward quite some time and we start to see cards like Seek the Wilds, a tool that would find action or lands and bam, green was on the map for card quality spells
You can save multiple deck lists to your account, making it easy to switch decks between games
Nevinyrral's Disk plus Darksteel Forge and Mycosynth Lattice also gets rancid and unfair