Gate Hound

Granting vigilance is cheap; this card insists you pay for it twice, once for the body and again for whatever Aura you stick on it before the keyword switches on. That conditional is the entire engineering problem. A 1/1 that does nothing until enchanted is two cards committed to a static buff that vigilance, frankly, rarely justifies on its own. The effect itself is a team-wide combat upgrade in the lineage of cards that let an aggressive board swing without surrendering the back rank, but the gating here is unusually punishing: the enchant clause funnels the whole engine into a single point of failure, since killing the Dog or bouncing the Aura turns the lights off for every creature you control. Most vigilance-granters either come stapled to a relevant body or hand the keyword out unconditionally; this one took the harder, worse path of asking a fragile creature to be both the payoff and the prerequisite. The result is a curiosity from an era still experimenting with how to price global keyword grants on creatures, landing on a structure that makes the upside contingent on surviving long enough to assemble it.