This is an incredibly broad area, so in order to pare down the amount of content I need to cover and to help you prepare for either SCG Columbus or Mythic Championship IV this weekend, Ill focus on the Modern format
While the wording on The Seriema is unhelpfully unclear, the existence of the leaked Station Lands shows that abilities are unlocked only after the Station threshold is clear
Enchantment - Class Pir, Imaginative Rascal Partner with Toothy, Imaginary Friend (When this creature enters, target player may put Toothy into their hand from their library, then shuffle.) If one or more counters would be put on a permanent your team controls, that many plus one of each of those kinds of counters are put on that permanent instead
However, you need to keep an eye on your opponent's creatures that may attack you or block Phlage, and build up enough cards in your graveyard to pay Phlage's escape cost