You can add one to: Choose up to one target artifact, up to one target creature, and up to one target land
In fact, Bloomburrow s other non-basic lands actually push you AWAY from multi-color drafting: they cant pay colored costs for noncreature spells or abilities, they have colored activation costs themselves, and they only interact with creature types associated with their color
The Knight is likely better, as First Strike tends to be superior to Vigilance in aggressive decks, and it puts the (not necessarily Basic) Plains onto the battlefield un tapped
That theory states that a spirit of pure mana, purer than even elementals, could exist simultaneously across all planes at all times
You can even select which permanent types to exile if you want to preserve part of your board
With the FINAL FANTASY franchise, we took a different approach