The only real way to kill a walker and feel ahead is to do so by attacking with guys you have in play or a counterspell
And at a full Commander table with four players, itll become a 9/9 creature very quickly
If you sink enough mana into its X cost, your opponents will either die or have no resources left to defend themselves, both on the battlefield and in their hand
The card types that can appear on cards exiled with Keen-Eyed Curator are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery
As mentioned above, most cards during the Card-E era utilized both the Long and Short format codes, although which used what depended on what set of the Card-E era were talking about