This means that every single creature in your deck works with Prosperous Thief, Ingenious Infiltrator, Yuriko, the Tiger's Shadow, and Kaito, Bane of Nightmares, which is a pretty significant power-boost to the non-ninja creatures in your deck
Gouging Fire #38 Pokemon Surging Sparks Keep track of your collection value over time
The best blue cards MTG has designed for control Force of Will , Mana Drain , and Fierce Guardianship all share this trait
We're getting to one
Creatures that fight when they ETB are a form of card advantage and tempo that the color desperately needs, and its usually nice to add to a big green creature rare or mythic rarity
If a deck can be built to contain mostly or only cards of that type, then the lands have no restriction other than the deckbuilding constraints