It is like the extreme version of running filter lands these days
Heres a look at each new Commander Deck, courtesy of Wizards of the Coast
Realmwalker As a shapeshifter and changeling Realmwalker gets the nod over all the other typal versions because it goes in any deck that can run green creatures, not just one
It shuts down activated abilitiesthink planeswalkers, fetch lands, or combo pieceswithout needing to target anything
Your primary route to victory will typically consist of overwhelming artifact token production leading to mass artifact sac to drain the table
A new card type, especially with a rules-bearing subtype, is an exceptionally high amount of work, but this is a pretty great example of how additional tasks fall out beyond the obvious work necessary to implement new mechanics