Sabertooth Nishoba

Protection from two of the five colors is the design choice that defines this Cat Beast Warrior, and the pair Wizards chose tells you who it was built to beat. Blue and red were the colors of tempo and burn at the time: once it resolves, the era's premier interaction (red burn, blue tap-down and steal effects, bounce that would otherwise reset it) simply slides off the body. The protection does nothing while the spell sits on the stack, so a blue counterspell still answers it cleanly; the wall it builds is a wall on the battlefield, not on the way down. A 5/5 with trample that ignores both halves of a controlling deck's combat and removal math is not a generically good midrange threat; it is a closer a Green-White ground deck leans on against an opponent whose primary colors hold no clean answer. The cost is the friction: six mana for a creature that any black removal spell or white wrath erases without trouble, which is precisely why the protection is aimed away from those colors and toward the decks that would otherwise have the easiest time keeping a creature off the board. The result is a threat tuned to a metagame question rather than a power-level target: in a room full of blue and red, it is nearly unanswerable in combat and on the board; in a room full of black, it is a slow, expensive trampler waiting to die to the first removal spell.