Many of these represent design philosophies about the color pie which have since been removed from the game, mostly the very powerful, but swingy color-specific abilities
Some keywords to be on the lookout for in an artifact deck include: affinity (for artifacts), improvise, bargain, craft, and metalcraft
It replaces the silver border with an acorn foil security stamp to denote that the cards are not for tournament play
Or as a well known combo goes, discard one
However, there are many shapeshifter creatures out there that dont have the changeling mechanic
The biggest exception that comes to mind is if you control a Wurmcoil (RG Tron), but the damage from that can be mitigated