Benthic Behemoth

Eight mana buys a 7/6 whose evasion is decided by the opponent, not the caster: Islandwalk turns this serpent unblockable against the deck that controls an Island and a slow vanilla body against everyone else. The relevance of the keyword sits entirely in the defender's hands, which makes the card a bet on what the opposing manabase looks like rather than a threat that stands on its own rate. Islandwalk is among the oldest landwalk keywords, a sideboard-grade ability dressed as a main-deck finisher: devastating in the blue mirror, dead weight against a deck that never touches the wrong basic. Stapling it to a body this expensive locks the whole package into that metagame gamble. The serpent is a clean ancestor of a long blue lineage of oversized closers that swing for lethal and dare the opponent to find an answer, but where later designs paid for evasion with rider flexibility (hexproof, ward, can't-be-countered clauses the caster controls), this one paid by handing the opponent an opt-out as simple as not playing Islands. Its ceiling is "unblockable seven-power beater," its floor "the most expensive vanilla creature in its color." Tempest sat at the hinge where Wizards was still learning to cost evasion whose relevance the defender governs; the modern instinct moved that decision to the caster. This is the older instinct preserved in amber.