White Scarab
Both clauses on this aura point at exactly one kind of opponent: the white deck across the table. The enchanted creature slips past white blockers, and the +2/+2 only switches on when an opponent controls a white permanent, so the bonus arrives precisely when the body needs to push through. This is sideboard philosophy printed at common, decades before sideboard cards were a developed craft. Against any non-white opponent the enchantment grants no stats and no evasion, a dead card committed before you know who you are facing; the conditional bonus is the tell. A flat +2/+2 would have made a generically playable cheap aura, but gating the bonus behind an opponent's white permanent trades reliability for a sharper edge, one that only bites when white is on the other side. White Scarab belongs to an old lineage of color-keyed reactive cards (the protection-from-a-color hosers and their kin) that asked players to read the table before deciding whether a card was a blank or a beating. The mechanic survives in spirit wherever a modern card scales against a named color; the all-or-nothing commitment of this version, a card that does nothing in a vacuum and a great deal against one specific deck, is what dates it.
