pokemon fossil most expensive cards - Antique Helix 153/165 - Pokemon 151 - Reverse Foil Stage 1 Fossil Pokemon Cards - Complete

Those that are typically are card disadvantage, such as Vampiric Tutor or Enlightened Tutor that don't put the fetched card into your hand

I believe the number one reason is the games evolution

Legality depends on the tournament format -- Baymax - Upgraded Robot can be legal in some formats and banned or restricted in others

This can include infinite turn combos with Aesi, Tyrant of Gyre Strait + Walk the Aeons + Mystic Sanctuary + Conduit of Worlds, or maybe some Landfall strategy with Scute Swarm + Tireless Provisioner + Perilous Forays

Phyrexian Rager 2.0 I love this little fellow but the power creep has made him look rather rusty

Tsuru and Tashigi are +2,000 Counter cards with the ability to reduce the cost of an opponents Character by 2