I will say this about Mangara, the Diplomat though: if you draw just 1 card on average per turn, then it's worth playing in Mono White decks
[8] The five basic lands are as follows: White lands, or Plains, which produce white mana Blue lands, or Islands, which produce blue mana Black lands, or Swamps, which produce black mana Red lands, or Mountains, which produce red mana Green lands, or Forests, which produce green mana There are also different kinds of lands (dual-lands and tri-lands, for example), but the most a beginner needs to know is that basic lands produce mana of one color only, and that multicolor lands can produce mana of two or more colors
Id recommend avoiding the each opponent mode unless itll win the game but across three choices with the other two modes, its not unrealistic to remove three or four permanents with this one card
As far as aesthetics, the sleeves look nice