Some of the most valuable metallic Pokmon cards include: The Shining Charizard
Air swirls, water flows, rock shards float, and fire arcs around him, all rendered with a multi-level foil process that gives the added impression of depth and movement
Having to already have evasive creatures to use this isnt a tremendous ask, but it cuts out a lot more of the top 50 creatures in any given color than you might expect
Getting a 2/2 with upside and drawing a Mountain is pretty good for 4 mana, and you can do it again from the graveyard
It can't be the target of spells or abilities, its static abilities have no effect on the game, its triggered abilities can't trigger, it can't attack or block, and so on